From: "Rich Peet" <>
> What causes a sound as seen on a waveform to go more positive or more
> negative than centerline?
Hi Rich!
The waveform asymmetry is caused by the presence of even harmonics produced
by whatever is making the sound. Human voice frequently exhibits such
asymmetry. So do brass instruments.
I see that you are a CoolEdit user (OK, Adobe Audition). You can experimen=
t
with this effect by using the Generate; Tones menu, and generating a tone o=
f
say A 220 and its second harmonic at the same level as the fundamental (tha=
t
is, both at 100%), and with a starting phase of 90 degrees. This will give
you a strongly asymmetrical waveform. This is not unlike many sound source=
s
in nature, where sometimes the fundamental is at a lower level than the
harmonics.
The last piece of info is that they asymmetry is audible. If you invert th=
e
waveform, it will sound different than if not inverted, at least with
low-frequency sounds and with headphones.
Eric
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