What are the risks from excessive sound?
The two main risks from exposure to high levels of sound are hearing loss and tinnitus (typically a ringing or hissing sound in the ears/head). Hearing can either be temporarily or sometimes permanantly affected, following even a single ‘acoustic event’. Tinnitus can also appear suddenly or more often as a gradual onset, following multiple exposures to loud events. Typically the name given to sound induced hearing loss is Noise Induced Hearing Loss (NIHL).
What increases these risks?
Sounds that can cause problems include short duration sounds (e.g. gunfire, explosions) and sounds that last a long time (e.g. listening to music at a gig or on personal headphones). The two key factors which affect the impact of sounds are; the loudness of the sound and the duration of the sound. For example, a brief explosion of a second or two may have the same impact as say 4 hours listening to a concert at high levels.
How are these risks measured?
Typically, sound level meters measure sound in decibels or dBA. Conversational speech is typically around 55 – 65 dBA. Sounds at 85 dBA can lead to hearing loss, if listened to for more than 8 hours at a time. Sounds over 85 dBA can damage your hearing quicker and there is a way to estimate the risks for different sound levels, For example, listening to music at 85 dBA for 8 hours has the same impact as listenting to the same music at 88 dBA for 4 hours and at 91 dBA for 2 hours. For every 3 dB decrease in level, the duration can be doubled for the same impact on your hearing.
Indicators of harmful levels of sound
You must raise your voice to be heard. You can’t hear or understand someone 3 feet away from you. Speech around you sounds muffled or dull after you leave the noisy area. You have pain or ringing in your ears after you hear the noise, called tinnitus. It can last for a few minutes or a few days.
What causes the damage to hearing?
A previous blog introduced how we hear Introduction to how we hear.
The tiny hair cells of which we have thousands in ear ear have delicate receptors (blue, reed like structures in the image). These can easily damaged by loud sounds which move the fluid in the inner ear causing these delicate structures to structurally change (think of tall, wild grasses, blown over by a strong wind).
Hair cells that are damaged by loud sounds do not send signals to the brain as well as they should. The first hair cells that are damaged are those that send high-pitched sounds to the brain. This can make sounds like /t/ in “tin”, /f/ in “sin”, or /k/ in “kin” harder to hear.
Short, loud noise, like an explosion, can also damage hair cells. Listening to loud sounds for a long time, for example, when you are at a music concert or a club, can also damage these hair cells.
Ringing in your ears, or tinnitus, is an early sign of noise-induced hearing loss. There is no way to fix damaged hair cells. Hearing aids can help you hear better, but your hearing will not come back on its own.
What can you do to limit the impact of sounds on your hearing?
First and this may sound obvious, if possible, listen at lower levels. Even reducing the sound by 3 dB can have a significant impact. Second, try not to listen to loud sounds as often. Third, use some type of hearing protection if you know you will be in an environment that you cannot control either of these two factors.
Thankfully, noise at work regulations are in place for work related noise (however if you are self-employed, you will have to manage the risks yourself). Also, many personal devices have limits which can be set to limit the sound levels from earphones and headphones.
If you are a musician and/or enjoy live music, consider investing in some custom made hearing protection. Hearing Protection
If you do feel that you are not hearing as well as you once did, or that you have tinnitus, make sure to get a thorough hearing assessment.
Paul at ‘The Hearing Space’ in Leeds has many years’ experience of advising people with hearing problems and has also had personal experience of tinnitus for many years (as a result of music).
Please get in touch to make an appointment Contact
T: 0113 8730444