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Comment by bch

7 years ago

So, a high frequency DTMF[0] construction should render a pre-echo? What’s the lowest definition of “high” pairs that would satisfy showing this encoding breakage but be hearable by a majority of people[1]?

[0] https://en.wikipedia.org/wiki/Dual-tone_multi-frequency_sign...

[1] https://en.m.wikipedia.org/wiki/Presbycusis

2 comments

bch

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vortico  7 years ago

No, pre-echos are unrelated to high-frequency sine waves. And DTMF aren't what I'd consider high-frequency. I'm talking about 4-20kHz.

  • bch  7 years ago

    Ahhh... I think I misunderstood your “dialup noises” as dial tone noises. You’re talking about the high pitched squelch-y initial negotiation of a modem.