Definition — Sone

The sone is a perceptually relevant unit that quantifies how loud a sound feels , rather than its physical energy. Its linear scaling makes it intuitive for comparing loudness differences, and it is essential in product design, architectural acoustics, and hearing research.

| Unit | Measures | Scale | Human Perception | |------|----------|-------|------------------| | | Perceived loudness | Linear (2 sones = twice as loud) | Directly proportional | | Decibel (dB SPL) | Sound pressure (physical) | Logarithmic | Not proportional | | Phon | Loudness level | Logarithmic (matches dB SPL at 1 kHz) | Scale for matching loudness | sone definition

1. Executive Summary

The sone is related to the decibel, but the relationship is non-linear. A common approximation used for converting sound pressure level (phon, a unit of loudness level) to sones is: The sone is a perceptually relevant unit that

| Sound Source | Approximate Sones | Approximate Phons / dB SPL | |--------------|------------------|----------------------------| | Quiet library, soft whisper | 1 sone | 40 dB | | Normal conversation (3-5 ft) | 2-4 sones | 50-60 dB | | Busy street traffic | 8-16 sones | 70-80 dB | | Loud music, vacuum cleaner | 32-64 sones | 90-100 dB | Executive Summary The sone is related to the

The is a unit of loudness , a psychoacoustic measure of how loud a sound is perceived by the human ear. Unlike physical measures of sound pressure (decibels), the sone scale is linear and directly proportional to perceived loudness. A sound rated as 2 sones is perceived as twice as loud as a sound rated as 1 sone.

This formula is an idealization. The exact sone value for a given dB SPL depends on frequency, as the human ear is not equally sensitive to all frequencies.