What unit is commonly used to measure sound intensity?

Sound intensity is commonly measured in decibels (dB), which provide a logarithmic scale that quantifies sound levels relative to a reference level. This scale is particularly useful because the human ear can detect an enormous range of sound pressures, and expressing this range logarithmically allows for a more manageable comparison of sounds. The decibel scale helps in understanding how changes in sound intensity can affect perception, allowing us to differentiate between faint sounds and louder noises.

The other units mentioned serve different purposes in the context of sound. Hertz measures the frequency of sound waves, indicating how many cycles occur per second. Pascal is a unit of pressure and can be used in acoustics to describe the pressure variations caused by sound waves, but it does not directly relate to sound intensity in the way decibels do. Watt, on the other hand, is a unit of power and is more applicable in the context of electrical energy or power output from sound sources but is not specific to measuring sound intensity itself. Thus, decibels are the standard for assessing sound intensity, making it the appropriate choice in this context.