What does frequency measure in sound waves?

Frequency in sound waves refers to how often the pressure of the sound wave alternates during a unit of time, typically measured in hertz (Hz). This measurement indicates the number of cycles of the sound wave that occur per second.

When frequency is increased, it results in higher-pitched sounds, while a lower frequency leads to lower-pitched sounds. This fundamental aspect of sound is critical for understanding how we perceive different tones and pitches in music and speech.

The other options mention concepts that are not directly related to frequency. Volume pertains to the amplitude of the sound wave, which affects how loud or soft a sound is, while tonal quality is related to timbre, which involves the characteristics that differentiate sounds of the same pitch. The distance between sound sources involves spatial concepts but does not connect to the frequency of sound waves themselves. Understanding frequency is essential for auditory perception, particularly in fields like audiology and hearing aid technology.