The consumer version of Dolby SR noise reduction. Dolby S-type noise reduction was derived from Dolby SR, and shares with it such developments as combining both fixed and sliding bands, anti-saturation, spectral skewing and modulation control. As a licensed technology (although Dolby makes professional S-type encoding equipment), it provides 24 dB of noise reduction at high frequencies and 10 dB at low frequencies. Modern high-end cassette decks generally contain Dolby S-type and give the home consumer the ability to make cassette tapes that sound like nearly as good as CD’s.