News & Information Blog

How does noise actually work?
You don’t need a physics background to understand it. When we talk about “sound waves,” we’re describing how vibrations move through the air. Imagine air molecules bumping into each other in a chain reaction — like ripples spreading across a lake after you toss in a pebble. That ripple is the sound wave traveling outward from the source.

You’ve probably noticed this in real life. When a car with a powerful sound system pulls up next to you and the bass is turned up, you don’t just hear it — you feel it. Your car may even vibrate. That’s because sound is pressure, and pressure moves in waves. Those pressure waves enter your ear and travel deeper into the ear canal until they reach the cochlea — the small, snail-shaped organ inside the inner ear.

The cochlea is filled with fluid and lined with thousands of tiny hair-like cells called cilia. When sound pressure reaches the cochlea, the fluid inside it moves, causing those hair cells to sway, much like seaweed drifting back and forth under a wave. Each one of these hair cells is tuned to respond to certain types of sounds.

Here’s what’s fascinating:
Not all hair cells respond to every sound. Different parts of the cochlea detect different frequencies. Higher-pitched sounds stimulate hair cells near the entrance of the cochlea, while lower-pitched sounds travel farther up the spiral before being detected. The brain receives these signals through the auditory nerve and interprets them as both pitch (frequency) and loudness (intensity).

Now, think about those times when you start your car in the morning and the radio seems way louder than you remember. That happens because your hair cells became fatigued the day before. This temporary condition is called Auditory Fatigue or Temporary Threshold Shift. After rest — ideally in a quiet environment — they recover, and your normal hearing sensitivity returns.

But if the exposure is too loud or too frequent, these hair cells can become damaged. And unlike many other cells in the body, once these hair cells are damaged, they do not repair themselves. This is known as a Standard (Permanent) Threshold Shift, and it means part of your hearing range is lost.

Noise-related hearing loss doesn’t usually happen all at once. It happens gradually — often so slowly you don’t notice until communication becomes difficult.