Bone Conduction Headphones

Social Media these days seems to be full of companies launching earphones that play music 'via the magic of bone conduction' and often pitch them as this meaning you cannot damage your hearing from the music heard via them, usually backed up by some very woolly and often incorrect science.

How you hear noise

There is only one way you hear something and that doesn't change no matter how the sound is presented to you. You hear via vibrations stimulating the tiny sensory cells in the cochlea and these cells trigger nerve impulses which the brain then interprets as a sound. There is no other way to hear, there is no way to by-pass the cochlea, and no way to hear anything at all other than via physical vibrations of the cells. You cannot send a vibrated sound 'directly to the brain' or 'to the nerves' as they have no means of receiving those vibrations and turning them into a signal the brain can recognise. 

Bone conduction is part of the way we hear every day, albeit a minor part, and is just the vibrations of the sound passing through your skull to the cochlea rather than reaching the cochlea via the vibrations passing through the air and into the ear. The two methods meet at the cochlea.

The cochlea can receive multiple input signals at once, from multiple noise sources and via bone conduction, which is a method by which we all hear every day.

Damage to hearing via bone conduction

There is a long and inglorious history of many many people damaging their hearing by bone conduction, going back decades, and this is among engineering staff in factories. It was common, and occasionally still is, for engineers to try and diagnose a problem in a motor by listening to it. What they would do is place a screwdriver against the housing of the motor and place their skull against the other side, just above or behind the ear. That would transmit the sounds from inside the motor directly to their ears via bone conduction, often enabling them to work out what was wrong within the motor without stripping it down. 

This is not without consequence however and resulted in thousands of people suffering hearing damage as a result of the bone conduction vibrations being passed directly to their cochlea from the motors. In a hearing test with someone exposed to noise you often see a dip in the results around the 6,000Hz frequency range, whereas with engineers who have been using this screwdriver trick you would see the drop in hearing ability to be focused more around the 4,000Hz range. I have done tens of thousands of hearing tests over the years and have seen this effect myself many times and it is still reasonably common to see even today.

Bone conduction can encourage excess noise

Bone conduction headset

One of the small benefits of in-ear headphones is that they can reduce external noises, even if only by a little. Even the cheapest in-ear headphones will stop a small amount of external noise getting into the ear which is better than none at all. Why is this important? Because for most people, the volume they set the music to is determined by how well they can hear the music over other background noises and the louder the background noise, the more they will turn the music up to drown it out. This more often than not, even for very modest background noise levels, means the in-ear volume of the music is well into the danger areas for causing hearing loss. 

With bone conduction headphones, there is nothing stopping the background noise entering the ears so the wearer hears that volume exactly as normal. That means they have to crank the bone conduction headphones up louder to hear the music clearly over the uninterrupted background noise, and as bone conduction is just stimulating the cochlea in the same was as normal headphones this means more sound in the form of vibration is still damaging the sensory cells.

This means the attendant risk of hearing damage is still there with bone conduction headphones, or it could be argued is even more likely than with in-ear headphones which are blocking some of the background noise.

Bone conduction headphone summary

There is no doubt that bone conduction headphones work - you can hear perfectly well via bone conduction (but with less clarity than regular headphones), but they are NOT safer than in-ear or over-ear headphones, do NOT reduce or eliminate the risk of hearing damage, can still damage hearing in just the same way as regular headphones, and offer no safety benefits to most people. Any company which is claiming bone conduction headphones somehow eliminate the risk of hearing damage is using nonsense-science to sell a myth. 

Away from these occasional spurious health claims they are not a bad product at all and have some good use-cases which some of the more reputable suppliers base their sales on:

  1. Some people who hate the pressure of in-hear headphones or the heat of over-hear headphones may find bone conduction ones to be a great solution, but that is about comfort and nothing to do with safety.
     
  2. They may also be good for motorcyclists and also lycra-clad pedal bikers who would be able to listen to music with nothing blocking their ears so enabling them to be more aware of other traffic around them.
     
  3. People with outer or middle-ear problems such as otosclerosis may benefit as the bone conduction headphones by-pass the outer and middle ear areas completely and send the sound straight to the cochlea.

Unfortunately these good use-cases are often buried in the nonsense that they cannot damage hearing or somehow present the sound in a way which is safer than regular headphones.

More noise goodness

Just a quickie to say that a page has now been added to the site specifically to provide free resources to people looking to manage noise risks at work. To date this includes:

All are available here and more free loveliness will be added over the forthcoming weeks and months.

Radios At Work - Good or Bad?

A lot of jobs in industry can be, let's face it, utterly dull to do hour after hour, day after day. For example I once came across two people whose jobs, for 12 hours a day, was to stand by a conveyor belt of pre-packed layered salads and as they went past, pat them to make sure nothing was sticking up before the lid was sealed on. Twelve hours a day patting salad must drive you crazy.

The temptation for many employers is to provide music via a PA system, to allow employees to wear headphones (under hearing protection if necessary), or provide hearing protection with built-in music players.

Site-Wide PA Systems

This sounds lovely but is a potentially big clash between the employer trying to be nice to their employees and the exposure limits set in the Noise Regs. If a music system is to be heard clearly then it needs to be well above the background noise levels, which due to the dark magic by which decibels work, means a good difference between the music and the background noise of the work, not just one or two decibels. 3dB is barely noticeable and you are probably looking at least at 10dB for the music to be heard over a consistent background noise.

If your site is at say 76dB then hearing protection is not needed, add a nice site-wide music system though and suddenly you are over the magic 85dB(A) limit. The Regs now say you have to do everything reasonably practicable to reduce the noise levels back to a safe volume, so that means turning the stereo off.

If your site noise is already at 90dB(A) then adding a loud music system which can be heard over that will be pushing your noise levels up even further so again, the first thing the Regs say you have to do is eliminate sources of excess noise, and that again is the music.

This is not just theoretical by the way. For example, I did a noise assessment years ago on a company making kitchen units. The daily average for the employees there was just around the 80 to 82dB(A) area, but then they had a damn big stereo blaring out which was pushing them over the 85dB(A) limit. Without the stereo they were fine, with it though they had to wear hearing protection and the employer now had a duty to remove it. This is far from the only time I have sen music systems as the main noise level in a workplace over the years. 

As a side note, if an employer is thinking of installing a music system then make sure it is distributed around the site so the volume is consistent, rather than relying on one or two very loud points blasting out as is often the case.

So site-wide PA systems can be a solution, but can also be a problem.

Headphones under hearing protection

No, just no. OK, next...

There is no point whatsoever in an employer having a noise level of say 90dB(A) and providing ear muffs which reduce the noise levels under the protector to about 70dB(A), then the employee sticks some ear bud headphones underneath the muff and adds that noise all back again by blasting the music out so it drowns out the remaining external noise.

It is worth noting that in the event of a claim for noise induced hearing loss the claimant would probably still win even though the hearing protection had been provided. There is no way to distinguish between hearing loss due to noisy machinery and hearing loss due to high volume music, it is exactly the same. As a claim is decided as 'on the balance of probabilities', i.e. the hearing loss may have been caused by work, then the fact the workplace was loud would probably be enough to swing it.

Hearing protection with built-in music

This one is a good solution, go for it.

There are many forms of hearing protection out there which have FM radios, wired AUX connectors or Bluetooth which can allow music to be played from a phone or other device to the wearer. Some also have two-way speech modules allowing headset-to-headset communication. They work by controlling the noise levels inside the headset and not allowing it to go into any dangerous volume territory. This way they reduce the background noise and add in enough music or radio to be heard while guaranteeing it is not reaching harmful levels.

These are far and away the best solution. And as you may guess, the most expensive one as well.

Peltor ProTac III which has a 3.5mm jack for connecting a phone or external bluetooth unit, around £56 exc VAT.

Peltor ProTac III which has a 3.5mm jack for connecting a phone or external bluetooth unit, around £56 exc VAT.

Possibilities of sharing the cost

Just a suggestion... It is illegal to make employees pay for PPE but technically I don't see why they can't be asked to contribute to units such as this as the reason for it is not safety related but for their own additional comfort. For example, you have a noise risk so make two kinds of plug and two kinds of muff available, for which employees cannot be charged, and they choose what works best for them. But then you could also have an approved radio or MP3 headset which can be used as well, with the employer chipping in the element which would be the same as the standard ear muffs provided, and the employee paying the rest. That way you have control by knowing that the hearing protection is suitable for the job, and aren't charging them for the PPE provided, but are giving them an option to relieve boredom with a fancier set of ear muffs chosen specifically for non-safety purposes, and are making a contribution towards that equal to the standard muffs. Everyone would seem to win. 

The Hearing Protection Data page of this site includes quite a few FM, Bluetooth and MP3 compatible hearing protectors if you want a gander at some. For example:

  • Peltor ProTac series have 3.5mm jacks, some also have Bluetooth
  • Peltor Alert have FM radio and 3.5mm jacks as well
  • Sync Electro has FM radio
  • Sensear has music connection
  • Pelto LiteCom have two-way radio for headset-to-headset communication and MP3 connections

Ear Candles - Utter Made-Uppery or Useful?

Over many years of doing noise assessments and tens of thousands of workplace hearing tests I've frequently come across the same myths understood as fact and one of the most persistent, indeed increasingly so, is ear candles being used to clear ear wax.

You too can look like a right twonk if you stick a candle in your ear and set fire to it.

You too can look like a right twonk if you stick a candle in your ear and set fire to it.

Where does one start with this..? The idea is that you put a special candle in your ear, light it and it draws out all the manky badness from within. Hopi Ear Candles they are called.

They are dressed up in the whole woolly 'alternative therapy' sector, which usually just means 'I want to play at being a doctor but didn't have the aptitude for the training and they won't let me play with the real medicine'.

Hopi Ear Candles are often also given mythical status by proponents as being an ancient or traditional healing method. There are even claims of them being used in Atlantis! How 'traditional' are they? Let's put it this way, the Hopi Tribal Council themselves say that the candles are nothing to do with them, have never been used by them, and have tried to sue the manufacturers to stop using the Hopi name and claiming a link.

To be clear - NO! Putting something in your ear and setting fire to it does not magically clear your ears out. Indeed it is worse than that, every scientific study has not only shown there is no beneficial effect at all, but that they are actually dangerous and more likely to cause harm. Who would have thought sticking something on fire in your ear could cause harm? Clearly not the chanting lentil-munching pseudo-science believing magicial magnetic bracelet wearing muppets who use these things. For example, the medical journal American Family Physician stated:

Ear candling also should be avoided. Ear candling is a practice in which a hollow candle is inserted into the external auditory canal and lit, with the patient lying on the opposite ear. In theory, the combination of heat and suction is supposed to remove earwax. However in trial ear candles neither created suction nor removed wax and actually led to occlusion with candle wax in persons who previously had clean ear canals. Primary care physicians may see complications from ear candling including candle wax occlusion, local burns, and tympanic membrane perforation.

Ear candle residue

So that is no effect, doctors seeing people with increased wax blockage and even burns and burst ear drums from using these things.

And all-praise Canada who have banned the sale of these ridiculous things.

Proponents often point to the CE mark given on the candles as proof that they are certified to do what they claim. CE marking has absolutely nothing to do with verifying claims of effectiveness but merely is a self-certification by the manufacturer that they will not cause harm. 

If you ever hear someone talking about ear candles, take them somewhere private and quiet, and give them a slap!

Audiometry for Agency Workers

Our beloved Noise Regs require health surveillance (audiometry) to be provided for people who are identified as being at risk from noise exposures at work, but what about Agency staff where the individuals are not directly employed by the company operating the site?

Over the years I have come across several Agencies trying to pass the requirement for providing (and therefore paying for) hearing tests for the individuals the Agency provides to the host employer operating the site. Let's be clear from the off on this:

It is the responsibility of the individual's employer to provide the necessary hearing tests, and for an Agency this is the AGENCY and not the host employer. The Agency is the employer.

I had to look into this in detail a few years ago when I came across an employer who had around 25 employees working in a high noise area but over the course of a year had in excess of 400 agency staff working in there. They were not there all at once as the Agency was contracted to provide a set number of staff but there was a very regular churn in the specific individuals sent to the site. The Agency were insisting the host employer was responsible for providing the hearing tests and audiometry programme but the difference between 25 and 400 was a massive financial impact, about £625 a year for just 25 people, or around £10,000 if all 400 Agency staff were included as well.

I looked into this in detail and it was clear that the responsibilities for the hearing tests rest with the Agency. This is covered in the HSE's L108, Controlling Noise at Work:

People who are not your employees

Sometimes your activities may cause employees of other employers to be exposed to noise, e.g. where contractors take noisy tools into quiet premises to do their job, or they go to do a quiet job in premises that are already noisy. Regulation 3(2) places duties on all the employers involved and each will have a responsibility:

(a)  to their own employees; and
(b) so far as is reasonably practicable, to any other person at work who is affected by the work they do.

This responsibility applies to all the duties under the Noise Regulations except health surveillance (regulation 9), which you do not have to provide for anyone other than your own employees, while you only need to provide information, instruction and training (regulation 10) to the employees of others in relation to the specific job they are doing for you.

Where contractors and sub-contractors are involved it is usually best for responsibilities to be set out in the contractual arrangements. 

As the host employer you do still need to have a risk assessment in place and train and inform the Agency staff on the noise risks present, but the Agency remains the 'employer' for the staff they provide and responsibility for providing audiometry / hearing tests rests with them.

Best ways for bursting an ear drum

Ear drum

An ear drum, or 'tympanic membrane' for those who like proper words, is the thin partition between the outer ear and the middle ear, sealing off the ear canal and is the bit which vibrates in response to sound waves hitting it and turns noise into something you can hear. Bursting or puncturing it is fairly common, if painful, and after many years of doing hearing tests around the country, these are some of the most cringe-worthy stories I have been told about how people burst their own ears...

1) The cotton bud and annoying house-mate

This may not quite be the most painful, see number 2 for that, but ranks as number one for me on the balance of both pain, and it has to be said, being a right numpty...

Cotton bud

The young Brummie in question was in the bathroom and on this particular day decided that his ears needed a good decrapifying so whipped out the cotton buds (or Q Tips to our Yankee brethren). He was having a good delve around in his right ear and got distracted and took his hand away, leaving it sticking out of his ear. His housemate then chose that moment to shout something to him causing him to turn around towards the door to hear him better, and in the close confines of the bathroom forgot about the cotton bud sticking out of his ear. He whacked the end of the cotton bud on the wall, sending it plunging right down his ear, destroying the ear drum. Apparently it hurt a lot!

And the lesson is, well there are two lessons actually. First is that cotton buds are the tool of Satan and you do not need to go digging around in your ears with them, and the second is that if you do feel a need for some aural excavations, don't leave them sticking out of your ears!  

2) The unfortunate welder

Welding

This one has to be far and away the most painful-sounding ear drum bursting I have come across... For those who are not familiar with welding, you get a lot of hot sparks of basically tiny superheated white-hot bits of metal flying up and around. That's what makes the impressive-looking sparks.

The chap in question was happily welding away and was not wearing hearing protection, which was perfectly fine as it had been established his average exposure over the day was below the 85dB(A) magic figure. As he welded he turned his head slightly and one of those white-hot blobs of molten metal got a perfect shot, right down his ear. Before it could cool the white-hot metal burned through the ear drum, fell through the middle ear and came to a rest against the cochlea, thankfully although still hot enough to burn it, it had cooled in these fractions of a second enough so that it didn't actually burn through.

One suspects more than a few naughty words may have been said and I can only begin to imagine the pain of a super-hot bit of metal burning its way down the ear and absolutely nothing can be done to stop it!

The take-away from this one is more serious: I would recommend all welders wear hearing protection whether it is noisy or not - block up those lug-holes!

3) Hair washing can be dangerous

One lady was washing her hair in the shower and, as she did every day, tipper her head to one side to let the water jets hit the side of her hair. Unfortunately on this occasion she lined up her ear canal perfectly with the water stream so a single jet shot straight down her ear and hit the ear drum. Ear drums are magic at converting sound into vibrations we can hear, but are not very strong so the water jet tore straight through it. She described the pain as 'pure agony'!

4) Don't let that sneeze out...

Sneeze

Have you ever wondered what could happen when you have to sneeze but circumstances dictate you hold it in, so do one of those mouth-closed quick-sneeze things? One lad who cam in for his hearing test told me he had a burst ear drum, so I had a look down the canal and indeed he had. In this case he had tried to keep a sneeze in a few days earlier... The middle ear inside the ear drum is connected to the back of your throat by a tiny tube. This is so you can equalise the pressure on the inside of the ear to match the outside so when you 'pop' your ears you are opening that tube to let air in or out. When this chap kept his sneeze in he sent a blast of over-pressured air up this tube into the middle ear, blowing out his ear drum with a single sneeze! 

And an honourable mention goes to

One chap who didn't burst his ear drum through any fault of his own, he just didn't realise he had. He came in for his hearing test and I asked if he had experienced any problems with his ears. He replied that he had been suffering from ear ache for a few days away but 'it just suddenly went away yesterday'. I had a look down his ear and could see a nice perforation right across the ear drum. It seems the ache had been due to an infection in the middle ear, with the accumulation of pus causing the ear drum to swell out causing the pain, until it eventually 'went away' when the ear drum finally burst. Nice.

In most cases of perforations ear drums do heal themselves by the way and in more serious cases a simple surgery can fix it.

Flare Audio ISOLATE ear plug marketing

Flare ISOLATE plugs and foam.jpeg

In the ISOLATE, Flare Audio have come up with an ear plug that is certainly very different to the standard types on offer by the major manufacturers, and accompany them by some very slick marketing. The ISOLATE and ISOLATE Pro plugs have pricing to match the marketing though, at £25 and £50 per pair respectively, but is the marking anything other than sales fluff? As someone who has spent the best part of two decades working in the noise safety area, and who has conducted many thousands of hearing tests on people, here are a few of their claims and statements examined more closely to see how true or accurate they are.

Flare ISOLATE plugs and tinnitus

Screen shot Flare Audio FAQ on 13/06/17, www.flareaudio.com/pages/flares-pro-faq

Screen shot Flare Audio FAQ on 13/06/17, www.flareaudio.com/pages/flares-pro-faq

This is a rather bold claim that the ISOLATE plugs will stop damaging sounds from entering your ears, and then a very clear statement that this "will prevent your tinnitus from worsening". To start to look at this we need to look at the causes of tinnitus, one of which is indeed noise, but also includes any ONE or more of these:

  • Getting older - that's not 'old', that's 'older' so middle-aged onwards.
  • Infections of the ear
  • Too much loud noise
  • A cold
  • A build-up of earwax
  • A bang on the head
  • Some medicines are called 'ototoxic' part of which means they can cause tinnitus, this can include fairly common antibiotics and aspirin.
  • High blood pressure
  • Diabetes

As well as all these there are many many more causes, added to which the NHS also says that one in three people with tinnitus has "no obvious problem with their ears or hearing".

So let's be clear, there are a lot of causes of tinnitus, and even with that big list, for a third of all tinnitus sufferers there is still no identifiable cause.

Oh, and by the way Flare, your statement that 'there is no cure for tinnitus' is deeply misleading. There is no cure for some forms of tinnitus but there is for other causes. You cannot simply blanket all causes into one and this is worrying and misleading for sufferers who may come across your statements in a web search.

In this light then Flare's blunt claim that their ISOLATE plugs "will prevent your tinnitus from worsening" is firmly in the marketing fluff side of things. If your tinnitus does happen to be caused by high noise exposure, and you are still having high noise exposure, then the ISOLATE plug will help, but then again so would any hearing protection. Which brings us nicely onto the second claim.

Result on tinnitus claims: Marketing fluff

ISOLATE plugs are superior and attenuate better

Screen shot Flare Audio FAQ on 13/06/17, www.flareaudio.com/pages/flares-pro-faq

Screen shot Flare Audio FAQ on 13/06/17, www.flareaudio.com/pages/flares-pro-faq

There are some key words in this. 'Superior', 'attenuate to a much greater level' and 'far more evenly'. This one is very easy to examine closely as Flare, like all other hearing protection manufacturers, have to have their plugs tested and certified, and that data can be compared. And handily I have already done this on the hearing protection data part of this site which lists around 200 types of protector and their performance levels.

Let's look at 'attenuate to a much greater level'. The simplest measure of this is called the SNR, Single Number Rating, which is an overall rating of how powerful the hearing protector is, in decibels, with the higher the number the more powerful the protector is.

The ISOLATE Pro have an SNR of 36dB, while the standard ISOLATE have an SNR of 35. These are good numbers, but as they 'superior to silicone, plastic and foam' ones?

Out of the already limited list of hearing protectors I have analysed there eleven types of hearing protector on the market which are more powerful than the ISOLATE Pro plugs, and eighteen which are more powerful than the standard ISOLATE.

Hearing protectors which are more powerful than the ISOLATE Pro

Hearing protectors which are more powerful than the ISOLATE Pro

It is of note that of the eleven products above, all bar one are ear plugs like the ISOLATE Pro, and have prices in the range of a few pence, compared to £50 for the ISOLATE Pro. 

So, the ISOLATE do not "attenuate to a much greater level" than silicone, plastic and foam plugs as claimed by Flare.

And their second claim of a far more even response over the frequency range? This again is easy to assess thanks to HML data. This is the number of decibels the plugs reduce noise levels by at the high, medium and low frequency ranges, again measured in decibels. The larger the difference between the three figures, the less evenly the protector reduces the noise by and the more it distorts the frequencies being heard.

The ISOLATE Pro have a HML of 35, 33, 31, meaning a range of 4dB, while the ISOLATE have a HML of 35, 32, 29 so a range of 6dB. That is again pretty good, but Flare are claiming their plugs are not just good but 'superior'. A quick and not-exhaustive study of the data identifies 16 types of hearing protection which have a lower range in their HML data than the ISOLATE Pro, and 30 which are better than the ISOLATE. 16th and 30th in a far from exhaustive list of hearing protection is not very 'superior'. 

For the record, the best ones on my list are Howard Leight Max Lite and the Arco Premium Plugs, both of which have a HML range of just 1dB so perform almost identically across the frequency range, and cost 16p and 12p respectively versus £25 and £50 for the ISOLATE and ISOLATE Pro.

Result on claims of being more powerful and even: This one is not so much marketing fluff as downright untrue.

Claims on just hearing through bone conduction

Screen shot Flare Audio FAQ on 13/06/17, www.flareaudio.com/pages/flares-pro-faq

Screen shot Flare Audio FAQ on 13/06/17, www.flareaudio.com/pages/flares-pro-faq

This is on the packaging of the ISOLATE plugs themselves.

This is on the packaging of the ISOLATE plugs themselves.

This is one Flare trot out very regularly in their social media posts and seems to be something of a slogan for them. There is no other way of putting this one other than it is utter, utter, utter bollocks. Complete crap. Made up tripe. It is such nonsense that it doesn't even deserve the respect of a carefully worded statement on it. The plugs do not block all sounds and leave bone-conduction as the only means of hearing something, they simply don't. The SNR and HML data above proves it. If you are in a noisy area of say 100dB(A), the ISOLATE will mean that about 65dB of sound still passes through the plug and into your ears. That is fine as 65dB is about the level of a quiet office, but it is still some noise. Yes, you will hear by bone conduction as well as you always do but still hear a lot via the normal route. Absolute marketing nonsense. 

Result on 'hearing by bone conduction only' claim: Absolute nonsense.

Summary on the ISOLATE and ISOLATE Pro marketing

Flare Audio make some damn good audio equipment but in that far more subjective world you can use marketing flights of fancy to describe your product. The move into hearing protection has brought them into a world of medical facts, well-documented and tested data and above all, a much greater need for honest accuracy. Flare however seem to still be using the hyperbole they are used to on the audio product side of things and this sits very very poorly in something as important as hearing protection. The ISOLATE and ISOLATE Pro plugs are good, and expensive, but they are just as good as other products on the market and absolutely do not live up to Flare's marketing claims, some of which are misleading, some of which have no basis in reality at all, and some of which make inaccurate and worrying statements on medical conditions which sufferers do not need to be reading.  

When is hearing protection compulsory?

This is a shortened version of a full page discussing this in detail here: Hearing protection - Optional or Compulsory.

The Noise Regs contain provision for both cases, so in some areas it is optional and in others it is compulsory, with the deciding factor being the noise exposures involved. 

80 to 84dB(A) - Optional

If the noise assessment identifies exposures in this range, then hearing protection must be provided by the employer, employees should be told it is available, they should be informed about the dangers of excess noise, and then it is up to them if they choose to wear it or not. Usage is therefore optional.

85dB(A) and over - Compulsory

Once the noise levels hit 85dB(A), then there is no choice but to wear hearing protection and it is no longer optional.

Employers enforcing hearing protection use from 80dB(A) onwards

An employer cannot do less than the Regulations but can do more and some choose to just have hearing protection set as mandatory from the 80dB(A) level upwards. This is perfectly fine in law and is a choice the employer can make if they really hate their employees. 

Do ear plugs make tinnitus worse?

Tintin

Over many years of bothering and annoying people about noise generally, one of the consistent questions that I've had come up is whether ear plugs make tinnitus worse. Or as one person called it, Tintinitus, which sounds more like an infection caught from a Belgian cartoon character.

Tinnitus at its most simple is the sensation of noise in one or both ears even though there is no external stimulus causing it. It may not be a 'real' noise but because the ear is signalling to the brain that there is a noise then it sounds just as real to the sufferer as if it were an external sound. It can also be loud - really loud! If the part of the ear which is causing the tinnitus is the part which normally tells the brain about a really loud external noise then to the brain the tinnitus is just as loud.

What causes tinnitus?

Here's an unhelpful answer - loads of stuff. For example, just some of them are:

  • Tiredness
  • A cold
  • Getting older - it is perfectly normal to get it as you get older
  • Stress
  • Some medication
  • Excess noise
  • Bangs on the head
  • Ear infections
  • Cardiovascular diseases
  • Diabetes
  • Being French
  • And the list goes on and on

(One of those is made up...) So here is one helpful tip: If, as I have seen online, a vendor of hearing protection makes a blunt claim that their ear plug will stop you getting tinnitus, they are talking nonsense and are just interested in selling something to you. Noise is ONE cause among many so wearing an ear plug MAY help IF the cause is noise. Looking at you 'sometimes a little too free with the marketing speak' Flare Audio...

What does tinnitus sound like?

Many people think of tinnitus as a clear whistle, and it can indeed be this, but it can take many forms. It can be a whooshing noise, the sound of wind through trees, a buzz saw, a pulsing noise with a beat (often linked to blood pressure), and so on. If however the sound in your head is a voice telling you to kill the Pope then this is not tinnitus... Joking aside, the effects of tinnitus should not be under-appreciated as living with this every day can be horrendous.

So, do ear plugs make tinnitus worse?

This one is an easy simple answer - no, no and thrice no. Ear plugs do not make tinnitus worse.

Ear plugs

What they can do is make it more noticeable though. For example, most people with just a mild tinnitus only notice it at night when it is quiet, the external noise dies down and stops swamping the sound of the tinnitus in their ears and they start to notice it. Ear plugs have the same effect - if they effectively reduce the external noise entering the ear then there is less going on in your ears with less external sound to drown out the tinnitus sounds, meaning it can become more noticeable. 

Ear plugs can help stop tinnitus getting any worse IF it is being caused by repeated exposures to high noise levels, by which I mean noises over 85dB(A), the kind of noise levels where you start to have to raise your voice or shout gently to have a conversation with someone. If you don't have that kind of regular exposure then ear plugs will probably be of no help at all.

An aside...

My favourite conversation about this came up when doing a noise assessment up in the Glasgow area. I was told with absolute certainty that 'if you put ear plugs in too deeply then they kill the hairs that sense the noise and make you deaf and cause tinnitus'. In this particular factory this was completely accepted as total fact by every worker in there, and everyone I spoke to knew it came from 'a doctor who told it to someone a while ago'. Although as with all these myths, nobody seemed to actually be the person this doctor had spoken to.

Path for plug to damage hair cells

This is IMPOSSIBLE. To get a plug in that deep you would have to shove it down the ear canal, bursting and through the ear drum (agony), carry on through the middle ear crushing the small bones in there (agony), through another drum (agony) and into the cochlea (agony and impossible). But no matter how much I tried to explain this, even drawing pictures of the insides of ears to help out, they were not for convincing as the urban myth was most definitely reality there!

High noise for company drivers

This is an area which I have avoided tackling head-on in the past and generally turned a blind eye to it as it is an area packed with uncertainty and potentially large issues to sort out, but nevertheless it is an interesting question - how do the Noise Regulations apply to people driving a vehicle on company business? This would cover the obvious such as truck or van drivers, but also motorcycle couriers, anyone driving a company car on a work-related journey, or indeed anyone driving their own car on a work-related journey. 

Are they 'at work'?

The Noise Regs apply to people who are classed as being 'at work', so the first question which needs to be considered is whether the people involved are actually 'at work' or not.

If they are driving to or from their normal place of work, then no, they are not at work. That's easy.

As a guide to if they are at work though, do they meet any one of these:

  • They can make a mileage claim for the journey.
  • They are driving to a place of work which is not their usual place.
  • They are making deliveries or transporting goods.
  • They are driving between places of work.
    Their journey forms part of their working hours.
  • They are on some kind of errand for the company or going to a meeting elsewhere than their normal place of work.

In all these cases, the driver is more than likely 'at work'. If they had an accident the HSE would probably class it as a work related accident and may investigate it as such. If the vehicle was faulty or the driver made to work too many hours by their employer, the company could face prosecution. So in these cases, the Noise Regs must apply as there is no exemption for driving.

Cirrus Dosebadge noise meter

Measuring the problem

To get an idea of the scale of the issue and to see if noise is indeed a problem in this situation I attached a noise meter in the form of a Cirrus Dosebadge to the passenger seatbelt where it would be free of any interference, with the seatbelt fastened into place across the seat. The stereo was deliberately on very quietly playing Radio 4 at a volume just loud enough to make out the speech over the wind, engine and tyre noise and if I'm honest, far quieter than it would be normally. The car was then driven for a couple of hours up the M5 and M6 to Manchester with the dosebadge sitting there taking a measurement for the entire journey. The car itself was a two year old Santa Fe Premium so pretty much spot-on a mid-range mid-price car.

Noise measurement result

The result was interesting, coming in at 87dB(A), especially when in reality the noise would in all likelihood be higher as the stereo was very much at an artificially low setting. 

This opens the door to a whole can of worms. If a decent newish car bring driven sensibly and even artificially quietly is coming in at 87dB(A), then it is eminently reasonable to expect most cars and especially vans to be at this level and higher. Assuming even only a 1dB increase in noise then that means four hours of exposure will bring the occupant to their daily limit, the point at which hearing protection then is required. Motorbike couriers will hit this even faster, within an hour if my own experience on a motorbike is anything to go by, with van drivers not far behind.

This means there is a huge pool of potentially millions of people out there who are exceeding the 85dB(A) limit while at work, but for whom there is, naturally, no pressure to wear hearing protection or take steps to reduce the noise again. How many companies look at in-cab noise when purchasing cars or vans? How many company specify cars and vans with no stereo when buying them for company personnel or use? Of course none do. How many even measure the noise in the cars being driven on company business, especially when this may include a myriad of private vehicles as well as company ones?

What to do about it?

This is the tricky part - we know there are a lot of people out there getting exposed at work to noise levels which if in a static workplace would require the use of hearing protection, inclusion in an audiometry programme, inclusion in noise awareness training programmes, and the company to look at ways of reducing the noise. 

If someone turned round and said they had a measured noise induced hearing loss and had been driving a lot on company business I can see no reason why that claim would not succeed.

Clearly, recommending people wear hearing protection when driving on company business is nuts and a complete non-starter, as are company rules banning the use of a stereo while driving which will push them over the 85dB(A) limit. There are some steps I would recommend an employer take though:

  1. When purchasing fleet vehicles have in-cab noise as one of the selection criteria which is at least looked at and considered in the purchasing process.
     
  2. Include people who drive a lot on company business in the noise awareness training programme as this includes identifying signs of ongoing noise induced hearing loss. This includes people who drive their own car or motorbike on company business as well as those in vehicles provided by work. This does not include people who only drive to and from their normal place of work.
     
  3. Include the same people who drive a lot on company business in the company hearing screening (audiometry) programme so any developing losses can be identified early.

The HSE and this issue

I think I can best sum up the HSE's stance on this so far as 'shhhh, for God's sake don't mention it as we don't want to get involved as it is going to be a total nightmare'. 

In April 2017 I emailed the HSE and got a very non-committal reply back which completely avoided the basic question being asked of 'what is your stance on this and how do you manage it in your own employees'. So I wrote to them again, a proper old fashioned letter, and a month later have still to receive a reply. Should I ever receive one I will add it here.

Civil claims and this issue

The HSE may be reticent to dive into this murky water, but you can bet anything you like that sooner or later someone is going to put a claim in against their employer for this, if they haven't already. If they have measured hearing loss and the employer has done nothing about it, then it is a reasonable argument that their hearing loss has been at least partly caused by their noise exposures when driving, and to me that meets the standard of 'on the balance of probabilities' upon which claims are decided. For me, therefore, employers should be taking steps to address this if only to prevent potential hearing loss in employees and to minimise their risk of a successful compensation claim, at least by following the advice in the 'what to do about it' section above.

Renting or buying noise meters?

Rent or buy?

This really comes down to how often you are thinking you will be using your noise meters. Here's a rough suggestion for how to work it out. 

  1. Have a ponder on how many days you think you will need to do decent noise measurements for your workplace.
  2. Look at what the rental cost would be for that number of days. 
  3. Look at the purchase price of a decent hand held meter, calibrator and maybe three or four personal wearable meters (dosemeters). 
  4. Get a quote for how much it will be to have them all calibrated (every two years remember, it doesn't have to be every year). 
  5. Add up your purchase and calibration prices.

You will probably be looking at something like every three years to do a full noise assessment for your site so you have that rental cost every three years, compared to the purchase and calibration costs. If you have say a ten year lifespan of the meters you are looking at three times the rental costs compared to the purchase and calibration costs.

Other considerations

There is one big advantage to having purchased your own noise meters, and this is the ability to respond quickly to changes in the workplace with no additional costs. For example, if the production department introduce new machinery or maybe relocate existing machinery, built a wall, etc. you can quickly update your assessment with new measurements.

If the site changes hours of work and working patterns such as job rotation by the way, you do not need to actually measure the noise again. You could simply take the existing measurements and recalculate exposures for maybe prolonged exposures in one are and reduced exposures in another. That is a job that doesn't necessarily mean actually remeasuring.

If your site changes the facility around a lot then that is another factor in favour of buying, whereas if it is fairly static then the balance is more back to the middle.

Click here for more information on how to choose noise meters

Most powerful hearing protector

Sometimes in a high noise area nothing beats the good old fashioned approach of 'most powerful is best' when it comes to hearing protection. But that doesn't always mean cost is a good indicator.   

Out of the 170+ types of hearing protector listed on the Hearing Protection Data page on this site, these are the top ones ranked by SNR, the single number which is an indicator of how powerful they are at reducing noise.  https://thenoisechap.com/noise-chat/most-powerful-hearing-protector

FullSizeRender.jpg

As you can see, of the top 17 only 3dB separates the top and the bottom but don't forget that a 3dB change is important as due to the frankly mad way decibels work, 3dB is equivalent to a doubling in the energy of the noise and therefore equitable to a doubling in the danger. So those which are 3dB higher are effectively offering double the level of protection offered. 

What is interesting is the price differences. The top of the list E-A-R Soft Fx plugs are around 27p each, while the ISOLATE Pro plugs rank in the bottom group but are £50 a pair! Cost is most definitely not an indicator of noise reduction ability. The ISOLATE Pro plugs are reusable, but then again so are the number two plug, the E-A-R Push-in which are only around 58p per pair. 

I would therefore caution anyone looking for the most powerful ear plug protection to start at the top of this list and work their way down - if you can spend a few pence for better protection then there is no point spending a hell of a lot more for slightly less proction. 

Reducing bass noises

Low frequency noises can be the hardest to reduce exposure to via hearing protectors, and none on the market can block low frequency (bass) noise completely, but which are the best?

Low frequency noise reduction

Out of the 170 different types of protector listed on the Hearing Protector Data page, here are the top ten with the strongest low-frequency noise reduction levels.

Interestingly all are plugs rather than muffs and the best-performing are the foam styles rather than the metal designs of the Flare Audio ISOLATE plugs.

More here.

Boosting iPhone Volume

This seems perhaps a little contrary for a chap with an unhealthy noise obsession, but I have an ongoing issue with needing to boost my iPhone's music volume beyond the maximum it will go to normally.

The issue is riding on a motorbike with an in-helmet audio system where the iPhone cannot quite get loud enough to be heard reasonably well over the wind noise at motorway speeds. But I'm not kamikaze about my hearing and there is some method to this seeming madness. 

With rough figures, let's say wind noise on a motorbike at 70mph is about 90dB(A), whereas the iPhone can get the music out to play at about 93dB(A). That 3dB difference is enough to just about hear something of the music over the wind noise but not clearly - that 3dB difference is what you are really listening to but is too small to be much use. 

Add to that I wear ear plugs to get the noise down and they work really well, unfortunately for both the wind noise and the music. The plugs reduce the wind noise to say 72dB(A) and then the music to 75dB(A), so you are still listening to that same 3dB difference, just at a quieter level and it's still too small. So, find a way of amplifying the iPhone music output to go above the stock maximum level and hopefully I can get wind noise to 72dB(A) but music up to about 80 to 82dB(A) so still very safe but a nice clear step up from the wind noise and with a good separation of music and background noise.

Equalizer app

A complication is that the helmet system is bluetooth-only so the commonly available headphone amplifiers don't work as they all want a cabled connection between the amplifier and the headphone, so I am trying an app-based approach. 

I deleted the stock Music app a while ago when Apple removed the ability to use star ratings in it and my normal music-playing app is Cesium now which is excellent. 

Equalizer playlist

First to try is the Equaliser app. I'm not entirely convinced by this one's design as there seems to be a myriad of paid levels and every time I try to do something it wants me to upgrade, but I have the free one and it has a volume boost (gain) setting which is supposed to add volume over and above the iPhone's normal maximum level.

I put the gain to maximum and it did make a difference. Although when I say 'a difference' I mean 'a difference if you listen really carefully in a quiet room' kind of difference. Maybe it adds something like 3dB which on one hand is good as that is doubling the energy of the noise, but to a human ear 3dB is pretty trivial.

What it did do though was add a lot of farting distortion to the music. Bass lines became really fuzzy and some vocals started sounding like the singer had used a landline phone to record themselves.

When I received a separate notification for things like new Twitter messages or Facebook posts, the app crashed. On a motorbike that means taking the next exit from the motorway, perching on the roundabout to start it up again, and then setting off. 

Not good and deleted. Next..! 

Surprising areas where your hearing is at risk

Noise at work is pretty well managed and everyone is well aware of the noise in a nightclub or a music concert where your ears are ringing or sounding a little dull afterwards, but there are other less obvious places where we get what can be very high noise exposures.

  1. The cinema.
    Once upon a time I was sat in a cinema watching a film (Dark Knight Rises - yes, I am that middle aged chap who goes to watch Batman films, tragic) and found myself wincing at some of the noise levels. As I had my meter with me and being a geek I did a quick measurement and found it was averaging around 100dB(A) and up to around 110dB(A) at the loudest bits.

    Assuming an average of 105dB(A) that means you have approximately five minutes until you hit the daily amount your ears can take and start to risk being damaged, while even at the lower 100dB(A) level, fifteen minutes is your maximum before the risk of damage starts.

    There are no limits on what you can be exposed to though as you are not at work and there are no staff in there to be exposed while the film is at it's loudest.
     
  2. Driving a car.
    I measured my car driving up the M6 with the stereo playing Radio 4 quietly enough to be clearly heard over the road and wind noise, but not loud, (and nowhere near as loud as I would have music normally). This came in at 87dB(A) meaning I would hit the 85dB(A) limit in around five hours. With the music on comfortably this would be more around the 90 to 93dB(A) level meaning hitting the limits and starting to risk hearing damage in about two and a half hours if at 90dB(A), or one an a quarter hours if it 93dB(A).

    High end car stereos, (you know the type, the ones where you hear the boom boom a minute before a clapped out lowered Golf with tinted windows comes around the corner) are often around 110 dB(A). And the music is inevitably shite which makes it even more dangerous. Possibly.
     
  3. Golfists and their golf bats.
    Hitting a golf ball with a titanium golf racket can give an impact noise of around 130dB. The duration is exceedingly short but repeated exposures to this can start to build up a problem.
     
  4. Crying baby.
    Babies can hit around 110dB, and also do so at just the right frequency to get into your head and almost hurt. This is no accident - your ear amplifies parts of the sound spectrum which are critical for speech enabling you to hear speech more clearly over background noise than you otherwise would, and babies can scream at exactly this frequency. It's roughly the same volume as a pneumatic drill digging up a road. 110dB for only a few minutes a day is loud enough to run the risk of causing hearing loss. Although in this case the silence would probably be most welcome.

    It is also massively amplified to about 140 million dB on an overnight flight when someone's tiny little noise and poo machine decides to let the whole plane know it's not happy.

Zero is not nothing

Decibels are odd things and you would think that zero decibels, 0dB, would mean silence but nope, that's way too obvious.

In a hearing test, the scale goes down to -10 or -20dB depending on the equipment being used and a lot of people can hear down to that level.

Audiogram example

Zero decibels was set by taking a reference group of people and finding the quietest sound they could hear and that was set as zero, meaning 0dB is considered to be the 'normal' threshold of human hearing. Zero decibels therefore is not an absence of sound but is in effect the reference point from which we assess whether hearing is deteriorating or not. 

As with any group-study though, there are always people who can hear better than the average and some who hear worse and typically it is young people who hear the best. Young women up to their early 20s particularly are usually very good with hearing levels that can hit -5, -10 or even -15dB at some frequencies, which then, like men, starts to drop away as they get older.

The theoretical value for complete silence by the way is -23dB, although nobody has ever measured that or got a room to achieve that level.

Flare ISOLATE plugs for motorbike riders.

Flare ISOLATE plugs for motorbike riders.

I ride a motorbike and at motorway speeds the wind noise is very high indeed inside the helmet - I would estimate it to be somewhere around 90dB(A). I also have an in-helmet audio system which I use for listening to music, podcasts or sat nav directions but when on motorways this has to be cranked up to full blast to try and overcome the wind noise. The wind noise on its own is enough to leave your ears ringing after a long motorway journey but then the audio system on top really pushes you over the edge.

So my questions were three-fold:

  1. Can the Flare ISOLATE ear plug control the wind noise?
  2. Can the ISOLATE plug really eliminate the wind noise and leave me just hearing the music?
  3. How comfortable are they long-term under a tight-fitting hemet?

 

Flare ISOLATE and ISOLATE PRO plugs for work

Flare ISOLATE and ISOLATE PRO plugs for work

Flare Audio have launched the ISOLATE and ISOLATEpro hearing protection ear plugs, accompanied by a blizzard of social media marketing, often including statements about 'switching off ears' and 'leaving you only hearing via bone conduction'. The ISOLATE and ISOLATEpro plugs certainly look good and Flare's claims for them are for extremely superior protection, but how do they perform in reality when looked at for use in the workplace, how much do they actually reduce noise by away from the marketing hype, how do they perform compared to other protection, how do they fit, and are they as good as the marketing claims? This post looks at each of these and includes the missing SNR, HML and APV data for both the ISOLATE and ISOLATEpro plugs. 

Loud people at work

An issue which I've come across a couple of times is whether the Noise Regs specifically deal with loud people at work. Two situations I've seen have been one where a chap constantly shouted over a fairly high background noise to the extent he alone was the difference between the other people in the area exceeding the 85dB(A) limit or not. The second was a quiet open plan office with one employee who frequently shouted across to other people and talked very loudly on the phone. In this case the office didn't exceed the 85dB(A) level but the person was definitely causing a noise nuisance.

A FAQ page on loud people at work has been added dealing with these two cases and how the Noise Regs apply to them.