How is frequency defined?

Frequency is defined as how often a vibration or periodic wave repeats itself within a given time frame, typically expressed in hertz (Hz), which represents the number of cycles per second. This concept is fundamental in acoustics and is particularly important in understanding sound waves, as different frequencies correspond to different pitches of sound.

In the context of hearing and auditory perception, frequency plays a crucial role because it affects how sounds are perceived by the human ear. Higher frequencies correspond to higher pitches, while lower frequencies correspond to lower pitches. The measurement of frequency is essential for various applications, including hearing assessments and designing sound-related technologies.

The other definitions provided touch on different aspects of sound but do not accurately describe what frequency is. Loudness relates to amplitude, sound intensity measures the power carried by sound waves, and duration refers to how long a sound lasts—all distinct concepts from frequency.