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 */
- CSS Values and Units Module Level 3
- Candidate Recommendation