🔋college physics i – introduction review

Phon

Written by the Fiveable Content Team • Last updated September 2025
Written by the Fiveable Content Team • Last updated September 2025

Definition

A phon is a unit of perceived loudness level for pure tones. It is numerically equal to the sound pressure level in decibels (dB) of a 1 kHz tone that is perceived as equally loud.

5 Must Know Facts For Your Next Test

  1. The phon scale is used to describe the subjective perception of loudness.
  2. At 1 kHz, the number of phons directly equals the number of decibels.
  3. Loudness levels in phons account for the frequency sensitivity of human hearing.
  4. A phon measurement adjusts for the fact that different frequencies are perceived with different sensitivities at the same sound pressure level.
  5. The concept was developed to create a standardized way to measure perceived loudness across various frequencies.

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