in some cases harmonics are produced by distortion in the microphone
preamplifier, if not set correctly (some small DATs had preamplifiers
that clipped at levels lower than 0 dB when signals were so high to
induce the user to rotate the level knob at values lower than 4); by
overloading the AD converter with levels that exceed 0dB; and, more
smoothly, with analog tapes by approaching and exceeding the maximum
recording level of the combination recorder+tape.
as higher frequencies are more directional, the level of harmonics
you see may also depend on the orientation of the singing bird:
maximum level of harmonics should be when the bird is in axis with
the microphone or parabola. a further element that alters the level
of harmonics is distance as higher frequencies attenuate more.
Gianni
At 18.48 13/11/2006, you wrote:
>When viewing bird song in Audition I see some songs display more
>harmonics than others, are these elements actually part of the song
>giving it timber or are some harmonics created with the program as it
>renders the sound?
>
>Gerald White Muscatine , IA
>
>
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Gianni Pavan
Centro Interdisciplinare di Bioacustica e Ricerche Ambientali
Universita' degli Studi di Pavia
Via Taramelli 24, 27100 PAVIA, ITALIA
Tel +39-0382-987874
Fax +39-02-700-32921
Web http://www.unipv.it/cibra
Email
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