Sound Cycles Per Unit Time: Frequency Explained

The question asks for the term that defines the number of cycles a sounding body completes in one unit of time.

Defining Frequency

Frequency is the measure of how often a repeating event occurs per unit of time. In the context of sound, it specifically refers to the number of complete oscillations or cycles a vibrating object (the sounding body) makes in one second. The standard unit for frequency is Hertz (Hz), where 1 Hz equals one cycle per second. Mathematically, it can be represented as:

$ f = \frac{\text{Number of cycles}}{\text{Time taken}} $

Therefore, the number of cycles a sounding body makes in each unit of time is precisely the definition of frequency.

Analyzing Other Options

The other options are related to sound but have different meanings:

• Pitch: This is the subjective perception of how high or low a sound is. While closely related to frequency (higher frequency is perceived as higher pitch), pitch is a perceptual quality, not the physical measure of cycles per time.
• Reverberation: This refers to the persistence of sound in a space after the original sound has stopped, due to multiple reflections. It is related to the time it takes for echoes to die out, not the rate of cycles.
• Sound intensity: This relates to the power carried by sound waves per unit area in a direction perpendicular to that area. It is associated with the amplitude or loudness of the sound, not the rate of its cycles.

Based on these definitions, frequency is the correct term for the number of cycles per unit time.