Explain compression in hearing aids.

• A. Increases the dynamic range to make all sounds equally loud.
• B. Amplifies only high-frequency sounds.
• C. Blocks all background noise.
• D. Reduces the dynamic range of sounds so soft sounds are audible while loud sounds remain comfortable.

Answer: (D)

Compression in hearing aids works by mapping a broad range of sound levels into a narrower, comfortable output range. Soft sounds receive more gain so they become audible, while louder sounds receive less gain to keep them from becoming uncomfortably loud. This brings soft sounds up into the listener’s usable range without letting loud sounds overwhelm their hearing. The result is a reduced dynamic range that still preserves important differences in sound levels, making everyday listening more comfortable.

This is why the option describing reducing the dynamic range so soft sounds are audible while loud sounds stay comfortable is correct. It’s not about blocking noise or amplifying only high frequencies, and it doesn’t unfold sounds so that all inputs are equally loud.