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The <frequency> CSS data type allows for the specification of the pitch of sounds, expressed as a number followed (without whitespace) by one of the frequency units: Hz and kHz.

Two units are available to specify pitch frequency:

  • Hz represents the number of cycles per second.
  • kHz represents the number of thousands of cycles per second (in other words, 1kHz equals 1000Hz).

For example, middle C (the middle note on a piano) is roughly 261Hz.


/* No CSS property currently specifies pitch, either for voice or other audio */

Related specifications

CSS Values and Units Module Level 3
Candidate Recommendation