My personal opinion (and a bit of knowledge) about hearing, ears, musicians, instruments, hearing protection and hearing care.

I have been thinking about writing this post for some time now. I usually only post about things which are directly related to my personal projects, but since I have been working with ‘ears’ since the beginning of 2006 I will make an exception. Specifically for musicians and music teachers there are a few things I would like to bring to light, set right and explain. I read quite a lot about the use of hearing protection, pathologies and other hearing problems and, to my personal knowledge and opinion, there is a lot of inaccurate information out there. Nevertheless one can take steps to prevent hearing damage by exposure to loud sounds, or music.

 

The basics: How the ear works

If you read the wiki article¹ or watch the youtube movie² about this you will soon learn that you have something called your outer, middle and inner ear. For people exposed to high sound pressure levels the initial damage, which you hardly notice by the way, first occurs in the inner ear. In the cochlea³ to be precise, and to be very precise, to the stereoscilia⁴ also called ‘hair cells’.

The human ear contains approximately 3000 inner hair cells aligned in a single row and roughly 12000 outer hair cells aligned in three parallel rows. Now there is a lot that can be said about hair cells, but in short, they provide the brain with stimuli. And the outer ones do it by dancing⁵.

If you make them dance too hard for too long, they break. And they don’t grow back. When this happens your ears sometimes ‘ring’ for some time. When the ringing stops, your brain has compensated for the damaged hair cells. When the ringing does not stop you have something called tinnitus⁶, which is truly horrible. There is a safety system built into your ear to prevent damage to your hair cells, but since this system is a bit outdated and our surroundings have changed quite a bit since its design, the effect is minimal. So how can you actually prevent damage to your ears?

 

First of all ask yourself: “What am I doing?” and “What’s the risk?

If you are, say a clarinet teacher, you have a double responsibility. As a professional musician you depend on your ears greatly, of course, but you are also responsible for the next generation of (professional) musicians. Caring for ears should be a part of learning how to play any instrument. For most instruments⁷ there have been studies trying to calculate what the average of the daily ‘dose’ of sound is. Most of the them show results that are damaging to the human ear. This makes ‘noise induced hearing loss’ (NIHL) a professional risk. The only way to make sure what exactly the risk is, is by measuring your exposure. This means that you have to measure the sound around you and average the measurements over time.

Measuring sound is very difficult, and decibels are very hard to understand due to the logarithmic scale (for instance 0dB+0dB=3dB, which means that every 3dB doubles the sound pressure level!). Fortunately some very intelligent folks have invented something called a dosimeter which is, simply put, a microphone with a memory that takes samples throughout your day.

There is one I know of suited for the average consumer that is affordable: the Personal Noise Dosimeter by Etymotic research. It displays your exposure in a percentage. And the extra information on interpreting the results provided on the manufacturers website is relatively helpful.

 

Secondly ask: “What can I do to prevent hearing damage?

Protecting your ears is essential, especially on the long run. Depending on your genes, your aging ears will get a condition called presbycusis⁸, or age-related hearing loss. This will be added to the NIHL you might have sustained during your life. This is usually the point when you start to notice the decline of your hearing, and the moment most of us take action to prevent further damage. The sad part being that by this time, it is too late. Things that people complain about at first, is that they are unable to follow a conversation in situations where there is a noisy background. Your brain simply can not discriminate the information gathered by your hearing anymore.

Thus prevention is key, and you can do it by compromise. The first being to simply play softer. This is easier said than done since almost all of our instruments have been going through huge changes in the past couple of centuries making them much louder than their early versions. And we like loudness. But why? Because it gives us a kick, the kick of playing something loud! More accurately, there is a tiny organ in inner ear called the saccule⁹. And one thing it does in addition to gathering sensory information to orientate the body in space, is produce hormones that make us feel, well, kind of horny. Some fish stimulate the production of those hormones by spawning, and some call the feeling ‘the kick of making music’. And yes, we can get addicted to the rush the hormones give us. For me it explains why the average 16 year old goes out every weekend to meet ‘the love of their life’ in places you can hardly have a normal conversation.

Other things you can do besides waring hearing protection is play with distance. Remember that an increase of 3dB doubles the sound pressure level; the same goes for reducing distance to the source of the sound by 50%. Which also means that if you double the distance you will decrease the sound pressure level by 3dB. In a student – teacher situation this can do a lot of good.

In orchestras the use of carefully placed sound screens can help some of the musicians. Of course the application of sound absorbent materials is a similar solution.

 

Last but not least, the things we all think about but never really use, but sometimes seem unavoidable: hearing protection

Perhaps one of the most paradoxal issues for professionals and people passionate about music. Here the real compromise begins. But hopefully only when you are conscious of your ears, how they work, your environment, instrument(s) and future. Otherwise I can assure you that any hearing protection you buy will end up somewhere in a bag, jacket, case or drawer, hardly ever used.

So, the real compromise starts to become clear. Playing with hearing protection is, for instance a for clarinettist, almost impossible. Additionally to the distortion of the natural sound, the occlusion effect¹⁰ occurs. And since your body, and this goes for almost all wind instruments, functions as a resonance chamber the occlusion effect will give you an entirely new perspective on how your instrument sounds. Making it very hard to play as you would without something stuffed in your ears – this can however provide you with an interesting new tool for practice. Secondly, you miss out on all the soft and high pitched overtones because of upward spread masking¹¹, which in turn makes it difficult to work on tone and intonation as you would normally. In some situations however this can be useful, for instance when playing amplified on stage in a small venue with bad monitoring. In that case hearing protection provides you with something I would call ‘passive internal in-ear monitoring’, but that only works if you play a wind instrument.

You also might have come across in-ear monitors, I won’t discuss these in this here but when used correctly, they can serve as hearing protection for musicians that mostly perform amplified.

There are, roughly put, two types of hearing protection: the ‘universal fit’ and the custom made kind. Now manufacturers like to say that only one kind works: “the kind of hearing protection you actually ware”. And although I agree, the only kind of protection you actually ware is the kind that fits, is easy to use and comfortable. Lets draw a little parallel here, between hearing protection and shoes. We all ware shoes, have a couple of different pairs depending on what we are going to do and we all accept that our feet need the protection. It should be the same with our hearing protection. Depending on the risk we might need some heavy duty protection or just a pair of slippers. For me personally when it comes to hearing protection I prefer the custom made kind, also called otoplastics or earmoulds. For musicians the choice is limited because we demand more from our protection than the average factory worker. To my knowledge there is only one type of filter that does this in an acceptable manner: the ER filters¹² by (again) Etymotic  Research, and no, I do not work for these guys. They have got three types, the ER-9, ER-15 and ER-25. These filters are fitted into custom earmoulds and you can use more than one pair of filters with your pair of earmolds, which to me is a great advantage over filters that you can’t change or adjust yourself. The ‘Musicians Earplugs‘ as Etymotic Research calls the finished product, are sold by licensed resellers worldwide. Now please realize that these might not be the type of hearing protection you would prefer. I read an article recently about someone who tried lots of different types and in the end chose the yellow foam plugs, which is okay by me. But if you were to ask me which is the most reliable and best hearing protection I know of it would not be the yellow foam earplugs.

So how do you choose the type of filter or ‘attenuation value’? Let me start by saying that the attenuation value is different for everyone. It varies from person to person depending on the size of your ear canal. If yours is small and short, the sound pressure level behind the hearing protection is higher than if you have a long and larger ear canal. So the same acoustic rules apply to the tiny space of your ear canal that would to any other space. This means the attenuation values of every single kind of hearing protector are far from the real reduction of sound printed on the packaging. The ISO standards (ISO 4869-1 and 4869-2) that are supposed to safeguard us as consumers are absolute rubbish¹³. And due to the varying complex shapes of our ear canals I know of no reliable method to actually measure the real attenuation you get from your hearing protection in real world circumstances. So where does this leave us? Well, back where we started actually with our most important instruments other than our musical instruments: our ears. Any compromise you use to protect your hearing is a good one. It might not be perfect nor will it guarantee you hearing’s safety, but it is de(a)finitely better than not protecting your hearing at all.

For me this means that I use the ER-9 as well as ER-15 filters on a regular basis. Of all the different kinds of hearing protection I have tried these work best for me, and with everything I know about the risks involved and the consequences thereof, I too forget to ware them occasionally.

 

So the final, quite predictable tips still are: ware your hearing protection and ultimately just take care of your hearing. For prevention is the only cure when it comes to hearing damage due to exposure to loud sounds.

 

If you have any questions or remarks, please leave a comment so others can profit as well.

Oh yes, I almost forgot, the two photos I used for this post keep fascinating me although their only relation to this topic could be playing softly. The one at the top is from the sleeve of the ECM New Series album “Exil” with compositions by Giya Kancheli and features Giya listening to the playing of Natalia Pschenitschnikova, and the bottom picture is from the sleeve of the “Ascenseur pour l’échafaud” soundtrack by Miles Davis and features Miles playing to the ear of Jeanne Moreau. I really enjoy the resemblance of these two moments and wonder whether Roberto Masotti, the photographer of the first photo, knows about the one with Miles in it…

 

¹  http://en.wikipedia.org/wiki/Ear
²  http://www.youtube.com/watch?v=PeTriGTENoc
³  http://en.wikipedia.org/wiki/Cochlea
⁴  http://en.wikipedia.org/wiki/Stereocilia_(inner_ear)
⁵  http://www.youtube.com/watch?v=Xo9bwQuYrRo
⁶  http://www.youtube.com/watch?v=OE5fIoveLoM
⁷  http://www.soundadvice.info/index.htm
⁸  http://en.wikipedia.org/wiki/Presbycusis
⁹  http://en.wikipedia.org/wiki/Saccule
¹⁰ http://en.wikipedia.org/wiki/Occlusion_effect
¹¹ http://en.wikipedia.org/wiki/Auditory_masking
¹² http://www.etymotic.com/ephp/erme.aspx
¹³ http://www.cdc.gov/niosh/docs/96-110/pdfs/96-110.pdf (see page 35-40)