How much is too much??

So is this too loud then?

The key thing to understand about noise induced hearing loss is that the damage caused by acoustic overstimulation is accumulative with regards to both volume and duration of exposure. This means that a very loud noise heard for a very short time may not cause damage if the duration is sufficiently short while a loud but fairly comfortable noise level might cause permanent damage if the duration is long enough. 

This led researchers to come up with the concept of permissible daily noise dosage which takes into account the total amount of noise encountered throughout the day. Remember it's not just the music you listen to and the concerts you go to, it’s the noise of rush hour traffic, lawnmowers, the nightclubs etc that also contributes to cochlear damage.

Exposure level (dBA)	National Institute for Occupational Safety and Health Standard Duration
85	8 hours
88	4 hours
91	2 hours
94	1 hours
95	45 min
97	30 min
100	15 min
103	7.5 min
110	1.5 min
115	28 seconds
120	9 seconds

Data from National Institute for Occupational Safety and Health (NIOSH). Criteria for a recommended standard: occupational noise exposure—revised criteria. Publication No. 98–12. Department of Health and Human Services, 1998.

Also because the decibel scale is logarithmic, notice that every 3 dB increase represents a doubling of sound intensity so don’t be fooled by the small increases in dB between loud and harmful sound levels, they actually are large increases in intensity.

 

In fact, the Australian government has recognized the need to enforce hearing protection laws in  the workplace by passing a series of legislation like the Occupational Health and Safety Regulations.

Here's a table of noise level output for common sources:

Sources of noise	Typical Noise output level (dB)
Conversation	60
Noisy restaurant/Gym/Fitness class	80-85
Circular saw/ Party/ motorcycle	88
Concert/ Live music venue	92
Major sporting event	93
Nightclub/ Rave/ Disco	97
Timpani and Bass drum rolls	106
Jet plane taking off	120
Firearm/ Jet engine	140
Rock concert/music peak	150

Data adapted from Dilon .H et al. Binge listening. Is exposure to leisure noise causing hearing loss in young Australians?

Keep in mind that the volume from personal music players/mixing studios contribute significantly to noise dosage because of the extended listening periods – one of the ways technology contributes to noise induced hearing loss (increased portability of mp3s, increased music storage, extended battery life). With the increasing trend in mp3 ownership,

be careful of the volumes mp3s are capable of putting out.

In a few CD player-headphone combinations, output exceeded 130 dB. In addition, when music is used to mask existing background noise, hearing damage is almost unavoidable.

Hopefully in light of the new information, you guys should be able to debunk the classic misconceptions about noise induced hearing loss. For example 'It doesn't hurt so its not damaging my ears' Well, the pain threshold for most people is 120 dB which is certainly high enough to permanently damage hearing. Also 'It's only for a little while' Look at the table, sounds levels at 100 dB, the sound level at lots of gigs can damage hearing in 15 minutes, but when was the last time you went for a gig that lasted 15 minutes? In fact, remember Pete Townshend? The loudest concert ever recorded as listed by the Guinness Book of Records was the concert by The Who at the Charlton Athletic Football Club, London, on 31 May 1976 with a volume level of 126 dB 32 meters from the stage! 



In summary, here's a series of questions that may be helpful to you in identifying if you are at risk of hearing damage and should be used as warning signs:

  1)  Do you notice ringing in your ears after noise exposure? Ringing in the ears (tinnitus) is a common byproduct of excessive noise exposure, it usually goes away after some hours or a day but too much of these incidents could lead to permanent tinnitus and noise induced hearing loss. If the tinnitus persists for an abnormally long time (eg more than 24 hours), seek prompt medical advice from a professional like an audiologist to get your ears examined.
  
 2)Do your ears hurt upon exposure to the music or sound? If the sound causes pain it is hazardous. The acoustic pain threshold is usually 120 dB so it is safe to say if the sound hurts your ears immediately seek a quieter environment, don’t be fooled that it doesn’t hurt after awhile even when the same sound is playing, it might mean that temporary hearing loss has occurred and the damage is ongoing, even if the pain has gone.

3)  Do voices sound muffled after you have been around music for an extended period of time?

  4) Does music sound distorted at the end of the day?

  5) Do you have difficulty listening to the radio in noisy settings or following conversations in a group?

If the answer is Yes to any of the above questions, it would be wise to seek protective measures and a visit to your audiologist might even be in order for a complete auditory evaluation

     

A Also as a rule of thumb, the noise level is about 80 dB if people have to raise their voices to be heard at a distance of 1 meter

   

  If people have to should to be heard at a distance of 1 meter, the noise level is about 90 dB,

  

  And if you have to shout in your friend’s ear to be heard over the noise, the noise level is …way too loud!

Problems, problems, problems. Well its not quite enough to be aware of the problems, we have to be able to solve them in order to enjoy the things music we love, safely. That's where the next section comes in

 

...The Solution!