When hearing is damaged by excess noise it is not simply a case of things getting quieter but that they get more muffled and indistinct first. This demonstration of what noise induced hearing loss sounds like uses a piece of music and then apples successive filters to mimic progressing hearing damage caused by excess noise.

Noise Induced Hearing Loss by the way is what used to be called Industrial Deafness. The change in name is because all excess noise does the same damage, whether it is loud music, gigs, DIY tools, motorbikes and so on, as well as workplace noise. The term ‘industrial deafness’ implied a cause which is often not actually the case.

For those who prefer reading to videos, the rest of the post below the video summarises the issues and you can listen to each filtered piece of music individually.

Demonstration of what noise induced hearing loss sounds like

The reason we do noise assessments and the reason noise safety is so important at work is because of how excess noise impacts hearing.

Loud noises kill part of your hearing but it is not the case that everything gets a bit quieter, at least not initially. Your ears are more sensitive to certain sounds than others, with the human ear being very much matched to the key sounds in speech, meaning we hear speech over and above other sounds.

A hearing test result chart showing perfect hearing - flat lines for both ears — *This is a hearing test result for someone who is young and has perfectly normal hearing. Their lines are broadly level meaning all frequencies are about the same.*

The problem is, excess noise damages hearing, and as we are more sensitive to speech, then it is specifically the ability hear speech which is damaged first. That means everything doesn’t get quieter, but things get less crisp, less clear, and sounds get muddied with speech starting to get buried into other noises.

The classic example of someone with noise damage in their hearing is the person sat in a pub who can hear what is going on over on the other side of the room but can’t hear what someone is saying who is right next to them.

Hearing test result graph showing some slight noise damage - a V shaped trough at the right hand side of each graph — This is a hearing test result for someone who is starting to develop some noise-related losses in their hearing. You get these dips at the high frequencies which correspond to the part of hearing which is most sensitive and most related to speech.

The music and the filters used

Album cover of Merry Hell's Blink And You'll Miss It album — *Merry Hell album*

I use this bit of music as a demonstration as it has two really useful parts. The first 20 seconds or so is mostly just the vocals, so equivalent to listening to someone speaking when there is no other background noise around. Then the band kick in and that is more equivalent to listening to someone speaking in places like a busy pub or restaurant, or listening to speech on a TV with loads of background music also playing.

The music by the way is Drunken Serenade by a thoroughly marvellous band called Merry Hell.

Link: Merry Hell website

The song is on their excellent album Blink… And You’ll Miss It. Give it a go. A previous incarnation of Merry Hell also wrote Fear of Falling, possibly the most perfect four minute song ever created by mankind - that’s worth a try as well, seek out The Tansads’ live album Drag Down The Moon.

Causes of the hearing loss

While a noise assessment naturally focuses on the workplace, it is important to stress that all excess noise has exactly the same impact on hearing, so it could be work but it could also be using headphones for music, clubs, gigs, frequent cinema going, DIY or gardening tools, a lot of driving or riding motorbikes, sport shooting, and on and on.

Demonstration of developing noise induced hearing loss

I would suggest you use either headphones, some external speakers or a laptop which has particularly good sound for this.

Everyone listening to it will hear it slightly differently depending on their own hearing, but what is important is the comparative change from piece to piece as the hearing gets worse.

Normal hearing

This is as it should sound in a perfect non-hearing-damage world.

A graph of a hearing test result showing perfect hearing

This is the music without any filters, just as-is. This is nice and flat hearing and this is someone in their 20s with normal good hearing. There have been no changes to the frequencies of the music.

You can hear the vocals nice and clearly, and when the band start up the vocal stay nicely separated from the music and it is still easy to pick up on what is being said.

Slight noise damage

Audiogram showing some noise damage - a trough at the right side of the graph.

Here there has started to be some noise-related damage to the hearing and the upper frequencies have started to drop a little. The music is still fine, just not quite got the sharpness or crispness it did originally.

The filters applied to this are the same as in the second graph above, so some slight reductions in the high frequencies corresponding to that circled v-shaped dip.

Heavier noise damage

hearing losses developing - graphs showing reduced lines in both ears — *The v-shaped reductions have got worse and it has also pulled in some of the wider frequencies as well.*

With this one, the noise damage has progressed and it is starting to have a bigger impact. You can still hear the vocals both on their own and with the music but the separation of the vocals and the music is starting to get lose, it is becoming one sound just with the vocals layered on top.

As well as being less clear, the music also sounds quieter as all the frequencies have been reduced, although still significantly more so at the frequencies most impacted by noise.

Deeper noise damage

Here, the vocals on their own are OK, if very quiet, but when the background noise kicks in then it really swamps the speech. With this, you have to really listen to it to get the words which is the same as someone sitting in the pub who is guessing what is being said using context or even a bit of lip reading.

Hearing test result grab showing some heavy noise-related losses — *Heavy noise damage in hearing.*

With this one, all the frequencies have started to be damaged, hence it is quieter, but it is also a lot more bass-heavy and ‘muddier’.

For someone with this level of noise damage in their hearing it will impact all areas of their daily life.

When someone has hearing like this it really does impact every area of their lives. TV drama companies love to put background music behind speech but for someone with this hearing all it means is the speech gets buried into the background noise.

As they can’t follow what’s being said they could turn the TV up, and they usually do, but all that does is make a muddy noise into a louder muddy noise, it doesn’t add clarity or intelligibility back to them.

Often they start to socially isolate a bit. There is no point going to a pub or restaurant if all you can hear is the rumble of everything going on around you but not hear what anyone is saying. You end up sitting a nodding a grinning but not really catching much of what is going on.

Noise damage like this is life-changing and is why noise assessments are so important and why noise is treated as such an important issue at work.