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Re: artifact in spectrogram created using Raven

Subject: Re: artifact in spectrogram created using Raven
From: "Ray Mansell" BCTess
Date: Mon Jul 16, 2012 3:57 pm ((PDT))
[John - the URL was incorrect - it has a trailing period that needs to be
removed]

Laura,

The short sample you posted appears to be quite badly clipped, although it
certainly sounds like a Nelson's Sparrow.

I also downloaded the longer sample, and applied a simple high-pass filter
to remove all the traffic noise below 1KHz. After that, many of the sparrow
calls seem to be more or less intact - you should be able to find at least
a few in there that do not have that strange 'hole' in the spectrogram.

Good luck...
Ray

On Mon, Jul 16, 2012 at 6:18 PM, rock_scallop
<>wrote:

> **
>
>
> Hi Laura,
> I could not access your SounCloud files for some reason. But nevertheless=
,
> from what you say below I am willing to bet the problem is in the MP3
> compression. Such visual(but not necessarily heard)artifacts are common
> with MP3. If the sound is loud enough, the quieter frequencies above and
> below it are somehow removed to save space.
>
> If you can, it is best to record in wav format at a minimum of
> 44.1kHz/16bit resolution. If you must record in MP3, use the highest
> bitrate available. Any bitrate less than 128kbps is likely to exhibit
> audible artifacts.
>
> John Hartog
> rockscallop.org
>
>
>









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