As far as it is believed, medicine is still a young science and in progress with respect to the appearance of our species. Since less than 200 years we know something about how our hearing works, with the discovery of the organ of Corti - 1851 - and then of the tonotopism of the auditory pathways - Brodman, 1909 -. To be extremely simple, our hearing works like a keyboard and strings start from each key, as in a piano, which do not emit sound but carry the stimulus to the receiver: our brain. Already during the journey there are stations to exchange informations, but it is especially after arriving at the auditory cortex that a wonderful orchestra is triggered, involving most of our brain.
The neurosciences of the last few decades proved us that the concept of the right and left hemisphere is wrong and outdated. Kleber, Zatorre, Zamorano, Mado Proverbio are just some of the leading authors in this field. In one of their most recent works (2021) Olzewska et Al showed us that the whole brain benefits from education in listening to music and performance.
Summer is a period that most easily leads us to make and listen to music, therefore to cultivate and develop our brains. But there is a hidden enemy. The organ of Corti, our keyboard, has a limit in withstanding sound intensity levels. Since sound propagates in waves, we might think our cochlear keyboard as a stretch of coast instead. Depending on the intensity of the waves motion and their repetition, homogeneous or not over time, it is natural to expect that the coast may change, due to an erosion mechanism. The change can be abrupt: a tsunami for example. A sound tsunami is called acute acoustic trauma and can develop from a blast or another type of abrupt and intense noise - the limit of OSHA, the Agency for Safety and Health in the workplace, is 140 dBSPL for acoustic impulse. Slow but steady erosion, such as that of background noise at intensity> 80dBA or higher, for a long time, will give chronic acoustic trauma. In both cases, whether I have given a hammer to my auditory keyboard, have upset my sensory coast, or have worn my instrument, my coast, day after day, the result does not change: the damage will impoverish the activity of my brain. Of ALL the areas involved.
So?? As for the coast we would put a breakwaves protection, adequate to the force we expect from the waves, there are practical tricks to listen and play, preventing as much as possible the risk of hearing damage.
WHO helps us. On 2 March, World Hearing Day, theme 2022 "to hear for life, be attentive to listening", the World Health Organization warned that over 1 billion people, aged 12 to 35, risk hearing damage due to prolonged exposure to high sound volumes.
The damage from intense noise / sound, as it is known, is generally permanent, so the WHO has made six recommendations for all event organizers:
Do not exceed 100 dBA
The measurement of that level must be done in vivo and with special tools by expert personnel (= it is not enough to trust the apps)
The acoustics of the spaces and the sound control systems in the event venues must be optimized to ensure a pleasant and healthy listening quality
The public should be provided with adequate hearing protectors with instructions on how to use them
Access to quiet areas must be provided to allow acoustic rest to people and reduce the risk of permanent damage
Inform and train staff in noise protection
(This is what the laws in force in Italy, and the guidelines for the music and recreational activities sector have already provided for 10 years)
This is true for the public, but especially for those who perform music and shows. A WHO publication has already been dedicated to this topic since 2015. We know that the fortissimo (fff) of a saxophone can reach the levels of a jackhammer. But even the brass of an orchestra reach intense levels. In fact, it is rather difficult that music, contemporary but also classical, will remain in intensity ranges lower than 80dBA. Exposure times must be reduced between 80 and 87 dBA and the Acoustic Protection Devices (PPE), described in the UNI EN 458: 2016 standard, must be adopted. Not always easy if you’re a musician or a singer.
Let's summarize some essential points:
Will the protector make me feel nothing anymore? Generally no. The protectors have a description of the attenuation by frequency bands. When listening to music, a linear attenuation is usually better - the same decibels on all bands - but for some types of music or instruments, more varied attenuations are better: more on the high frequencies, more on the low ones … Usually you will loose the background noise, with speech/sing perception enhancement.
How long does the protector last? if I use the foam inserts (those pink, yellow-pink sponges…) they last from 1 to 7 days. Those in synthetic (plastic that I squeeze a little) and the bows from 1 week to 1 month. The custom-made hearing protectors, the silicone ones, which are molded to my ear canals, last up to 6 years, but should be checked after 3 to make sure the silicone has no cracks or my duct has "adapted" - a bit like checking shoes, which over time can expand and lose their shape-. The ear muffs themselves are not eternal, on the contrary: every 6 months it is good to check elasticity, cleanliness, defects of the bearings - and eventually replace them - while the headphones last from 1 to 4 years.
Do they need to be cleaned? Of course yes! The synthetic inserts can be washed several times by hand, under running water, with neutral soap - but also with a little alcoholic gel - the ones we are using for the hands - if we have any doubts about possible infections. The headphones can be cleaned with a damp cloth.
For those who, musicians, singers, ... must use in-ear, it is absolutely recommended to do an audiometric test first, to give the sound engineer the useful indications for the settings suitable for me. Otherwise the risk of unnecessarily forcing the voice or loosing sound alignment with others is really significant and hence the increased risk of damage - as well as poor performance -
Even those who do not use in-ear can use protectors with filters, which generally reduce the perceived sound by 15, 25 decibels. The most natural recommendation is to use in-ears, protectors with filters "during" the individual preparation and also in rehearsals, so as to arrive at the show already accustomed to that type of listening. Just like learning to walk in ski boots or to use work gloves.
But how am I aware of the noise? Generally my ears are a good sound level meter, especially if they start to hurt, but it's like measuring how hot a flame is with your fingers: better not risk them. Apps that measure loudness are often not reliable and underestimate. Of course, if I see the water in the bottle tremble, it's best to get away.
And how long does it take for my ears to recover from initial acoustic trauma? Not less than 16 hours. Therefore, if I cannot guarantee myself such a period of silence, better wear a suitable protector and enjoy the show.
But what do you want might happen after all? Do I have to lockdown in my holidays too? Of course not,. But better not to ruin my hearing, since there are no medicines that can make me recover it.
To get an idea of how a person with more and more hearing damage feels, there are some sites, such as Suva CH, which you can find in the bibliography. And maybe it will be more effective than my words.
Good music and happy holidays to all!
Bibliography
Olszewska AM, Gaca M, Herman AM, Jednoróg K and Marchewka A (2021) How Musical Training Shapes the Adult Brain: Predispositions and Neuroplasticity. Front. Neurosci. 15:630829. doi: 10.3389/fnins.2021.630829
http://www.lavoro.gov.it/NR/rdonlyres/38A6D1CF-533C-4D8E-AF6D-758CCDE884E7/0/LG_art_198_musica_articolato.pdf.
https://apps.who.int/iris/bitstream/handle/10665/154589/9789241508513_eng.pdf