The speed of sound is defined as the distance a point on a wave travels per unit time, usually represented by λ/T.

Noise is unpleasant, while music, with its rich quality, is pleasant to hear.

A sound produced by multiple frequencies is described as a note, often perceived as pleasant due to its complexity.

A sound of single frequency is called a tone, characterized by its purity and absence of overtones or harmonics.

The quality, or timbre, distinguishes sounds with the same pitch and loudness, with rich quality being more pleasant.