Sitting in the room, with cans the size of melons on my head, I raised my left hand. I was signaling that my left ear could hear the sound. Hearing testing in grade school was simple – pass or fail. But when was the last time you thought about testing your hearing? Mixing music, you have to know the capabilities of your ears. Unfortunately, with age and use, you and I can't hear frequencies as well as our younger days. This means our mix quality is going to suffer unless we know what to do.
Hearing sensitivity to sound is nonlinear. Our ears hear frequencies at different volumes. Frequencies that are sub-500 Hz must have an increased volume for us to hear them. Frequencies above 4000 Hz suffer the same. This means that a sound at 60 Hz (such as a bass note) is not perceived to be as loud as a sound at 1000 Hz even if they are played at the same decibel level.
The exact scientific frequency-to-dB-level relationship, mentioned above, was recorded in 1956 by Robinson-Dadson and later reviewed and slightly modified by Fletcher Munson in 1993. The difference was an increase in the amount of decibels required to hear low end sounds. Bass boomers beware!
A simple example proves out the nonlinear behavior of our ears. Find a song with a wide sonic arrangement. Listen to it at low volume and pick out the instruments. Now turn it up much louder and you'll hear more distinct sound – primarily in those low end and high end ranges.
Right out of the gate, our ears are naturally more sensitive to the mid-range frequencies. Things are about to get worse.
Our ears work via tiny hairs inside that pick up sound waves and change them into the nerve signals. The brain interprets the signals as sound. Hearing loss occurs when these tiny hairs inside the ear are damaged or die. The hair cells do not grow back, so most hearing loss is permanent. Hearing loss can be a combination of age, noise exposure, and/or genetics. Simply put, as we age, we experience natural hearing loss. I'd show you a chart of the frequency loss, but I figure this post is depressing enough. Toss in a lifetime of the occasional loud noises and I'll ask you this question…how good are the ears of a 50 year old versus a 15 year old?
As a brief aside, symptoms of hearing problems include;
- Certain sounds seem overly loud
- Difficulty hearing things in noisy areas
- High-pitched sounds such as "s" or "th" are hard to distinguish from one another
- Men's voices are easier to hear than women’s.
- Other people's voices sound mumbled or slurred
- Ringing in the ears
Wide Receivers run slower, baseball players hit shorter, and sound tech's suffer from hearing loss. Motivating, isn't it?
There are a few things we can do to prevent excessive hearing loss.
- Stay clean. Wax buildup negatively affects your hearing. There are plenty of over the counter products to clear out wax.
- Get tested. If you know you don't hear well in the 6000 Hz range, then you know to be careful not to boost those levels when you are EQ'ing.
- Use protection. Use earplugs when mowing your yard, using power tools, flying, etc.
- And by all means, whatever you do, be careful with your volume levels when listing to music, especially through headphones.
One final note, there can be times in which you should wear ear protection when you are running sound. This subject in itself is worthy of another article…but not today.
Question(s): Have You Ever Had Ringing In Your Ears? How Long Did It Last?