Sound
Science

A fluid-filled spiral structure in the ear that converts sound vibration into nerve impulses
Cochlea
A fluid-filled spiral structure in the ear that converts sound vibration into nerve impulses. Cochlea. The cochlea is the part of your inner ear that helps you hear by turning sound waves into signals your brain can understand.

The change in pitch of a sound when the source is moving relative to the listener
Doppler effect
The change in pitch of a sound when the source is moving relative to the listener. Doppler effect. It is a phenomenon where the frequency of a sound or light wave changes because the source or observer is moving.

The difference between sounds having the same pitch and loudness
Sound quality
The difference between sounds having the same pitch and loudness. Sound quality. Sound quality is what makes two sounds different even if they have the same pitch and loudness, like a piano and a violin playing the same note.