Frequencies are used with Aural CSS
properties to indicate the frequency of a sound effect for a page.
Frequencies are given as a number followed by a frequency unit. Values
cannot be negative.
Frequency Units in CSS
Hz
[CSS2|CSS2.1]
Description: Hertz. A basic unit of sound wave
frequency. 1 Hertz = 1 cycle per second.
kHz
[CSS2|CSS2.1]
Description: Kilohertz. 1 Kilohertz = One
thousand Hertz.