What is the measurement of the number of cycles per second that a sound source vibrates?

The measurement of the number of cycles per second that a sound source vibrates is known as frequency. Frequency quantifies how many times a sound wave oscillates in one second and is measured in hertz (Hz). In standard terms, one hertz is equal to one cycle per second.

While 'hertz' refers to the unit of measurement for frequency, it is not a direct term for the concept itself, which is why frequency is the more accurate answer in this context. Additionally, volume refers to the perceived loudness of a sound, while amplitude measures the extent of the sound wave's displacement. These concepts are related to sound but do not measure the cycles of vibration directly. Thus, frequency is the appropriate term for the number of cycles per second of a vibrating sound source.