Definition of phon in English:

phon

noun

  • A unit of the perceived loudness of sounds.

    • ‘The use of the phon as a unit of loudness is an improvement over just quoting the level in decibels.’
    • ‘Coincidentally, one phon is approximately the smallest detectable difference in loudness.’

Origin

1930s: from Greek phōnē sound.

Pronunciation:

phon

/fän/