Assistant Laboratory Animal Technician (ALAT) Practice Exam

What unit is used to measure loudness?

1. Hertz

2. Watt

3. Decibel

4. Bar

The correct answer is: Decibel

Loudness is measured in decibels (dB). This unit quantifies sound intensity and is a logarithmic scale that describes the ratio of a particular sound to a reference level, which is typically the threshold of hearing. Decibels are widely used in various fields, including acoustics, audio engineering, and noise pollution measurement, to express sound levels in a way that corresponds to human perception of loudness. Hertz is a unit that measures frequency, indicating how many cycles of a wave occur per second. Watt measures power, particularly in electricity and acoustics, measuring the rate of energy transfer. The bar is a unit of pressure and is not related to the measurement of sound or loudness. Thus, understanding that decibels provide a standardized way to discuss loudness helps clarify why this is the appropriate unit for that purpose.