Yes, there's a spectrum option in Audacity's Analysis menu. I think Sonic
Visualiser also does it, perhaps even live as you play the track?
Playing with it, if I was trying to use it to determine either the highest or
the loudest frequency in a call, I'd be wondering what I should set the "size"
parameter to. Its value has a dramatic effect on the resulting graph.
I'm under the impression that a large value makes the graph more accurate for
low frequencies, and a low value is best for high frequencies. So if I was
trying to determine the highest frequency, I should set it to a low value? But
how low? Doesn't it depend on how high that frequency is?
Obviously I don't know what that frequency is yet, so how do I know what to set
it to? Similar problem for the highest frequency.
What does one do? In practice, is there a FFT window size setting that everyone
uses to determine these things?
And for the highest frequency, how does one distinguish the call from mic hiss,
etc?
Peter Shute
> -----Original Message-----
> From:
> On Behalf Of Avocet
> Sent: Thursday, 22 November 2012 2:49 AM
> To:
> Subject: Re: [Nature Recordists] Re: Determining peak frequencies
>
>
>
> > Raven Lite's the only sound analysis software with which
> I'm familiar;
> > this is probably unreasonable, but do you happen to know of
> any very
> > inexpensive software that can generate power spectrum charts?
>
> Alan,
>
> Audacity - it's free. It does both audiograms and power
> spectra and is worth putting up with a few fiddly wrinkles.
> http://audacity.sourceforge.net
>
> Sorry to be picky over the terminology but "peak frequency"
> can be taken to mean the highest frequency or the frequency
> at the highest level which is really the peak power frequency
> which can be anywhere in the call.
>
> If I have a variable pitch call I would select the peak
> frequency (highest frequency) and plot the power at that
> frequency on the power spectrum. If I want the peak power
> frequency (over the lenght of a
> call) the power spectrum plotted over the whole call provides this.
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