[ntp:questions] Accuracy of audio tones via VOIP

Rob nomail at example.com
Wed Jul 10 08:11:44 UTC 2013

Robert Scott <no-one at notreal.invalid> wrote:
> No, I am not interested in time.  I am talking about frequency.  If
> you call 1-303-499-7111 you will hear the audio that is transmitted on
> WWV, which includes 500 Hz and 600 Hz tones.  As transmitted these
> tones are as accurate as NIST can make them.  But as received they
> might appear at a different frequency.

Then don't use that as a reference, I would say.
Even over the normal phone network, while the tones may be very accurate
there is not so much you can use them for, because the local determination
of their frequency will always be far less accurate for tones that short.

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