Comparedwiththefullrangeof humanhearing,thespeakingvoice coversa relativelynarrowfrequency band- roughlyfrom 100 Hzto 6kHz. Withinthatrange,thepowerdistributionofspeechis heavilyweightedin thefrequenciesbelowabout1kHz, withsome80 percentoftheenergy concentratedintherangebelow 500 Hz.