How we Hear – The Basics
The mystery or our hearing is not so mysterious when you understand how it works. Our ears pick up sound waves from everything around us. As we walk through life – sound waves are everywhere – in the air. Every time the phone rings or a dog barks; when you play the radio – these are sound waves. All around us, every minute of the day we are bombarded with sound.
In scientific terms, sound waves are measured as frequencies and amplitudes. All the sounds we hear are a mix of frequencies and amplitudes.
Sound waves travel through air, they are invisible to the eye but they affect the atmospheric pressure in the background many times per second. This is called a Hertz and each one represents one wave cycle per second. If our hearing is perfect, the human ear’s hearing ranges from 20 Hz to 20,000 Hz. As you move away from the sound, the pressure drops roughly in proportion to the distance you move.
Amplitude measures the height and depth of a sound wave. Amplitude, or loudness, is measured in decibels and we can hear over a range amplitudes. As the height and depth rises and falls, the sound wave varies to increase or decrease the volume.
How do our Ears Hear?
Human ears are very complex. The outer ear collects sound waves and sends them down the ear canal to set the eardrum in motion. In turn, the vibrations travel to the spiral shaped cochlea which is filled with fluid and minute hairs. When sounds waves hit the hairs, nerve endings spring into action to send impulses to the brain which turns the sound waves into the sounds we hear.
If we are exposed to loud constant noise, the hair cells may be damaged – temporarily or permanently. Something like a gunshot or a car backfire can cause instant hearing loss.
Look after your Hearing
Make looking after your hearing a habit. Use earplugs when working with loud machinery. Stay away from high pitched engines and noisy construction equipment. When listening to music, keep the sound at a reasonable level, whether you use headsets or not.
When you use a telephone headset, don’t listen for long with the volume turned up too loud. The louder the music, and longer you listen, the more likely your hearing may be affected. When changing your headset from device to device, you may find the sound level vary, but if it ever causes you discomfort stop using the headset immediately. The following are a few basic guidelines to help you protect your hearing:
- Turn the volume down before putting your headset on.
- Don’t listen to loud music for extended periods of time through your headset.
- Try not to turn up the volume to block out background noise in your environment.
- Keep the volume low enough so you can hear people around you talking.
