Re: SONY PCM-D50 field recordings with inbuilt mics

["picnet2" picnet2]

Hi,
    The Edirol R09HR's internal mics respond at > 40 Khz, heres a sonogram of 
an ultrasonic mouse repeller: 

http://urlme.net/bl/pests/mouse.png

Baudline can filter, decimate and shift frequencies around.

An example: Not quite nature, but can anyone guess what this is?
http://www.urlme.net/bl/rec/mystery1.wav
(Warning, loud high pitched tones, turn volume down before playing)

BR,
Mike.



--- In  "Raimund Specht" <> 
wrote:
>
> Hi Phil and Patrick,
> 
> yes, it is indeed very simple to make this kind of conversion. I used the 
> (expensive) Avisoft-SASLab Pro software 
> (http://www.avisoft.com/soundanalysis.htm) for this, but it can also be made 
> with any other sound editing software such as Audacity. On Audacity, the 
> corresponding command is titled "Set Rate" > "Other...", which can be found 
> on the pop-up menu that appears when you click at the tiny black arrow on the 
> left of the track representation.
> 
> I just investigated the frequency response of the PCM D-50 microphones a bit 
> further. They seem to be quite sensitive up to about 30 kHz. That's the 
> reason why they worked so good for the relatively low-frequency echolocation 
> calls of the Noctule bat. They still work beyond 30 kHz, but the sensitivity 
> drops significantly at those frequencies. So, the results would not be as 
> good when recording other bat species such the Pipistrelle for instance.
> 
> Regards,
> Raimund  
> 
> --- In  ". m u r m e r ." <murmer@> wrote:
> >
> > Raimund Specht wrote:
> > > 2. Modifying the sample rate attribute in the file header from 96 kHz to 
> > > 5.5 kHz, which stretches the time scale by a factor of 17.45 = 96 kHz / 
> > > 5.5 kHz. As a result, the ultrasonic bat calls move down into our hearing 
> > > range.
> > 
> > 
> > forgive me if this is a foolish question, but how do you directly modify 
> > the sample rate attribute in a soundfile header?  do you need a 
> > particular piece of software?  this seems like a spookily simple way to 
> > do a basic time-stretch, quite enticing...
> > 
> > best,
> > patrick
> > 
> > -- 
> 
> 
> --- In  Philip Tyler <macmang4125@> wrote:
> >
> > Hi Raimund
> > 
> > Many thanks for the info. I understand everything except the "Modifying the 
> > sample rate attribute in the file header"?
> > 
> > What do you use to do that, if I may ask?
> > 
> > Regards 
> > 
> > Phil
>