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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 4:00 pm ((PDT))
OK - I was wrong. It isn't clipped. That's what happens when a novice has
an opinion :-)

Ray

On Mon, Jul 16, 2012 at 6:57 PM, Ray Mansell <> wrote:

> [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 i=
t
> certainly sounds like a Nelson's Sparrow.
>
> I also downloaded the longer sample, and applied a simple high-pass filte=
r
> to remove all the traffic noise below 1KHz. After that, many of the sparr=
ow
> calls seem to be more or less intact - you should be able to find at leas=
t
> 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 <=
g
> > 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 ab=
ove
>> 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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