We live in a pretty noisy world; we are surrounded by the noise of cars, transport trucks, loud music, construction noise, and machinery noise, recreational noise from motorcycles, snowmobiles, chainsaws, power tools and the list goes on.  By now most of us know that repeated exposure to certain volumes of sound can damage our hearing.  But how do we know when sounds are too loud?  How do we know when to avoid loud sounds or wear hearing protection?

To answer those questions a little background information is required.

Research has shown that the amount of damage caused by noise exposure or loud sounds depends primarily on how loud the sound is and how long you are exposed to the noise.  The louder the sound, the less time you can be exposed to the sound before damaging hour hearing.

Loudness is usually measured and described in decibels.  The table below lists the typical volume levels in decibels for common sounds. The table also lists volume levels that are considered safe or too loud depending on the length of time you are exposed.  As you can see from the table, you can be exposed to moderate traffic noise (85dB) for 8 hours before damage could occur or 2 hours on a lawnmower (91dB) but once the sound is loud enough any exposure, even for a few seconds, there can be instantaneous non reversible damage to your hearing.

There are government standards in place that specify the volume of noise we can safely be around on an 8 hour day.  The current standards state that exposure to sound over an average of 85dB for an 8 hour period can potentially damage your hearing.  Most of us don’t carry around a sound level meter to see if we are being exposed to sound levels over 85dB.  An easier method is to follow this general rule of thumb; if you have to raise your voice to talk to someone an arm’s length away, you should be wearing hearing protection or reducing the volume if possible.

It’s worth noting that noise exposure can be accumulative, a little noise here, a little noise there and you wind up damaging your hearing.  The safe approach is to reduce your noise exposure wherever possible.

Table 1.
Maximum Recommended Noise Exposure Noise Levels

0 unlimited threshold of hearing
30 unlimited whisper
60 unlimited normal conversation
70 unlimited shower
85 8 hrs traffic noise
88 4 hrs snowblower
91 2 hrs lawnmower
94 1 hr food processor
97 .5 loud passage in movie theater
100 .25 hr riding motorcycle
112 1 minute Rock Concert
124 3 seconds Balloon Popping
140 Immediate Damage Firearms