Phon

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.

Review Questions

• What does one phon represent at a frequency of 1 kHz?
• Why are phons preferred over decibels when discussing perceived loudness?
• How does the human ear's frequency sensitivity affect measurements in phons?

Related terms

Decibel (dB): A logarithmic unit used to measure sound intensity. It quantifies sound levels relative to a reference level.

Loudness:

The perception of the intensity of a sound by a listener, often measured in phons or sones.

Frequency Sensitivity: The varying sensitivity of human hearing across different frequencies, affecting how loud sounds are perceived.