What is a decibel used to measure?

A decibel is a unit of measurement used specifically to quantify the intensity of sound. This logarithmic scale reflects the relative loudness of sounds perceived by human ears and is commonly used in acoustics. The scale helps to express sound levels in a way that aligns with human hearing perception, allowing for comparisons between different sound intensities.

For instance, sounds measured in decibels can indicate how much louder one sound is compared to another. A decibel level of 0 represents the threshold of hearing, while levels above 60 typically correspond to everyday sounds, and anything above 120 can be painful to a human ear. This underscores the significance of using decibels to gauge sound intensity effectively, making it crucial in various fields like music, engineering, and environmental science.

In contrast, the other options represent different measurements: length is measured in units such as meters, weight is typically expressed in grams or kilograms, and speed of light is assessed in meters per second. Each of these categories involves distinct principles and units that do not relate to the concept of sound intensity, emphasizing the unique function of decibels within acoustics.