What is the unit of relative loudness?

Answer 1

There are the loudness level LN in phons and the loudness N in sones

Scroll down to related links and look for more on correlation between sones and phons.

Answer 2

The unit of relative loudness is the sone. The unit for absolute loudness, or loudness level, is the phon. Both relative and absolute loudness are perceptual measures that vary from person to person.

The unit used to measure sound pressure is the dB (decibel). Since dB measures the power of a sound wave, a physical characteristic, it is not a perceptual measure but a scientific one (thus perception of the sound has no effect on it).

One phon is defined as equal to a 1 dB pure tone with a frequency of 1000 Hz or cycles per second.

One sone is defined as equal to 40 phons.

These references allow comparisons of loudness perception of different sounds that have different characteristics of intensity, frequency, and duration.

Answer 3

There is no unit for loudness. If you meant the units that loudness is measured in then it is known as frequency. Frequency is measure in hertz and the vibrations in seconds are decibels.

Answer 4

Decibels