On 2018-03-01, Dennis Lee Bieber <wlfr...@ix.netcom.com> wrote: > The bandwidth normally used for voice grade telephone traffic is closer > to 6kHz (say 300Hz to 6.3kHz)
Wow, that's pretty high -- where was that? Back when I was designing telephony electronics in US in the late 80's, POTS bandwidth was 3KHz: 300-3.3K. That same bandpass spec was used for the audio stages in the first couple generations of AMPS cellular mobile phones. The Codecs used in digital telephony (e.g. a T1 trunk) used 7-bit converts with 8KHz sampling, which means a cutoff frequency below 4KHz. -- Grant -- https://mail.python.org/mailman/listinfo/python-list
