Vic wrote:
Volker wrote:
> a signal delayed by less than 5-8 milliseconds causes a hollowness.
If
> the delay is less than 2 milliseconds the human ear cannot detect an
> echo.
> The awareness of echo depends of course on (the combination of)
> various effects, e.g. the frequency response and sidetone masking
> rating (STMR) of the sidetone path.
> You can find some information on effects related to sidetone in the
G
> series papers of the ITU-T.
I fully agree with the statement but must add that one should not make
absolute statements about ears, because the good Lord didn't give all of us
cochlea with
the same response time. Ergo, some humans may hear echoes, where others
hear nothing of the sort.
Ciao,
Vic
---
You are totally right Vic.
Since all ears are different (and the brains needed to analyse the sound
signal) you must be carefull making statement about ears in terms of exact
values.
The different behaviour of human ears and therefore the different kinds of
perception of echos is caused by psycho-acoustic effects, the response time
can be neglected.
The values mentioned above can be taken as a rule of thumb. Even if the
listener does not hear an echo he will at least be disturbed or annoyed
resulting in the impression of a low quality telephone connection.
Volker
