Worlds of David Darling
Encyclopedia of Science
   
Home > Encyclopedia of Science

phon





A unit of loudness of sound. The intensity of sound to be measured is compared by the human ear to a reference tone of 2 × 10-5 pascal sound pressure and 1,000 hertz frequency. The intensity of the reference tone is increased until it appears to be equal in loudness to the sound being measured; the loudness of this sound in phons is then equal to the number of decibels by which the reference tone has had to be increased.


Related categories

   • ACOUSTICS AND MUSIC
   • UNITS