So what exactly is sound? Well, sound comes from vibrations which produce waves that travel through the air that we breathe in order to reach our ears and be heard. Now inside of the cochlea in our ears are tiny little hairs that are moved by the vibrations in the air. When the vibrations cause the hairs inside of our ears to move, the hairs turn the vibrations into electrical signals that which are then transmitted to our brains in order to make sense of them. Now these tiny hairs inside of our ears are a very delicate and sensitive thing. When the volume of sound gets too loud these hairs can be damaged. When they are damaged from hearing too much noise these hairs fall off. This is what causes hearing loss. As more and more of these hairs fall off the worse your hearing loss becomes. To make things even worse these hairs do not ever grow back once they are gone. This is the reason that hearing damage/loss is permanent and cannot be repaired once the damage has already been done.
So what is a safe level of sound? Well, the answer to this question is surprisingly complex. It is actually possible for any sound that is 85 decibels or higher to cause hearing damage. The other important factor in determining how much sound is too much for your ears is the duration of exposure. It is generally recommended that you have no more than 15 minutes of exposure to sound of 100 decibels. This is roughly the maximum volume of many MP3 players and other portable music devices that we typically use on a day-to-day basis. The louder that the sound gets the less time that it takes to cause hearing loss. Exposure to any sounds of 110 decibels or greater places you at risk of permanent hearing damage with anything longer than 1 minute of exposure.
So what are some simple tests to determine whether or not the sound that you are being exposed to is too much? Your ears will usually give you some warning signs that that the sound that you are hearing is too loud. One general indicator that that noise around you is too loud is that you have to raise your voice to be understood by people that are close by to you. Another obvious sign is that the noise hurts your ears. The threshold for pain is roughly 120 decibels which is as loud as a jet engine at takeoff. A third and somewhat more subtle way to know whether or not the noise is too great is if your ears ring after listening to a sound. This often happens to people after going to loud concerts or possible listening to loud music on headphones for a while.
In the end your hearing is a very precious sense. Once it is gone it is gone forever so if you find yourself in a situation where you are experiencing too much noise take some simple steps to protect yourself. The first way you can protect your ears from noise is to just simply walk away from the loud sound. If you are unable to simply walk away from the excessive noise then you should put earplugs in your ears. Lastly, avoid listening to excessively loud music for long periods of time. We all have to put away our headphones from time to time.