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2. Re: Advice needed for cleaning up this recording

Subject: 2. Re: Advice needed for cleaning up this recording
From: "vickipowys" vpowys
Date: Mon Dec 5, 2011 1:03 pm ((PST))
Hi Mike,

The only problem with your example is that we were trying to show the  
harmonics below 4 kHz (on the original they are just visible for at  
least some of the calls), and your example seems to have wiped them  
all away.

Spectral Layers looks good as a noise reduction application though,  
but pricey, $700 - $2200, yikes!  I like the way it could remove the  
background siren in the demo recording on their website.

Vicki



On 06/12/2011, at 3:20 AM, Mike Rooke wrote:

> Hi All,
>           Heres a new application which Ive used on the recording.
>
> First an example from the original recording (no changes) - then  
> the isolated call extracted, followed by the original with some  
> background noise removed and again the call on its own with more  
> amplification. -Quite an easy task in spectral layers, see the  
> tutorial file section on the website for more info.
>
> http://urlme.net/audio/spectrallayers.mp3
>
> The application web site:
>
> http://www.divideframe.com/?p=spectrallayers
>
> Now to remove that generator humming away in my beech recording...
>
> BR
> Mike.
>
> --- In  vickipowys  
> <> wrote:
>>
>> Peter,
>>
>> All your questions about the frogs are interesting ones and of course
>> I don't know the answers.  Except to say I think it is just one frog
>> giving the calls.
>>
>> In my experience of living for 15 years in an area where there are
>> quite a few GT Frogs about, I had never heard this call before until
>> a couple of years ago, and it was a very long time before I was able
>> to get a recording.  The call would occur briefly about once each
>> night during the summer.  I kept microphones on my front verandah
>> because I was also doing some research on night birds.  That way I
>> was eventually able to pick up a recording and much later tracked it
>> down to Green Tree Frog distress call.
>>
>> At one stage a small goanna got into my ceiling and ate some frogs,
>> but the frogs then gave a different sort of distress call, more of a
>> moaning shriek.  I have picked up the frogs with my hands and they
>> make no sound at all, or maybe just a brief croak.  It was only with
>> the mice attacking them that the frogs gave this shrill call.  I
>> don't know why the frogs didn't simply hop away.  I suppose the mice
>> just chased them and nipped at their feet until they could not hop
>> any more.
>>
>> I have also heard GT Frogs occasionally give a sharp yapping call.
>> Mostly of course they just give a loud and rhythmic croak-croak-croak
>> call, especially when it is hot and raining.
>>
>>
>> Vicki
>>
>>
>>
>> On 05/12/2011, at 8:52 AM, Peter Shute wrote:
>>
>>> OK, good, I hadn't noticed that parameter before, and it makes
>>> quite a difference. I do see the faint bands now. I'll sent Tom
>>> Tarrant the link to your sonogram, and he can decide for himself.
>>>
>>> Now I'm curious to know what was happening to the frog. And was it
>>> one frog, or a series of frogs being attacked by something one by
>>> one? I'm also curious to know why this call is apparently uncommon
>>> on Tom's recordings - I would have thought froggy death was a daily
>>> occurrence in that habitat. Perhaps it's normally too swift. (I'm
>>> not expecting any answers to these questions.)
>>>
>>> Peter Shute
>>>
>>> ________________________________
>>> From: 
>>>  On Behalf Of vickipowys
>>> Sent: Monday, 5 December 2011 8:12 AM
>>> To: 
>>> Subject: Re: [Nature Recordists] Re: Advice needed for cleaning up
>>> this recording
>>>
>>>
>>>
>>> Peter,
>>>
>>> Yep, FFT = the sharpness setting in Raven Lite. In some applications
>>> it is called FFT (Fast Fourier Transform).
>>>
>>> Basically when you are adjusting any sonogram settings, you simply
>>> juggle the available settings until you get an image as clear as
>>> possible and that suits your needs. A less contrasty sonogram is
>>> more likely to show up some of the less obvious aspects of the
>>> sound. A more contrasty sonogram can be useful for publication,
>>> provided you already have a good clear sound to work with.
>>>
>>> I like to work with black and white (which is useful for  
>>> publication)
>>> altho some members on this list prefer to work with colour for on
>>> screen analyses.
>>>
>>> For anyone using Izotope, the lovely sonograms that it produces can
>>> be set to white on black, but not black on white. But it is easy to
>>> invert the image using photoshop so that you get black on white. You
>>> need to take a screen shot of the Izotope screen first, to work  
>>> with.
>>>
>>> Vicki
>>>
>>> On 05/12/2011, at 5:31 AM, Peter Shute wrote:
>>>
>>>> FFT? Where do I set that in Raven Lite? All I see is a third
>>>> adjustment called "sharpness".
>>>>
>>>> Peter Shute
>>>>
>>>> ________________________________
>>>> From: <naturerecordists%
>>>> 40yahoogroups.com>
>>>> <naturerecordists%
>>>> 40yahoogroups.com>] On Behalf Of vickipowys
>>>> <vickipowys%40skymesh.com.au>]
>>>> Sent: Sunday, 4 December 2011 2:20 PM
>>>> To: <naturerecordists%
>>>> 40yahoogroups.com>
>>>> Subject: Re: [Nature Recordists] Re: Advice needed for cleaning up
>>>> this recording
>>>>
>>>>
>>>>
>>>> Peter,
>>>>
>>>> You are quite right to be suspicious of the effects filtering may
>>>> have on a sonogram. So let's go back to the original.
>>>>
>>>> If you look at the left hand channel of the original recording in
>>>> Raven Lite, with the settings at 50 darkness and 50 contrast,  
>>>> and FFT
>>>> size 2516, that may help. Expand the sonogram window so that you  
>>>> are
>>>> seeing about 1 minute of sound, and only up to 10 kHz, then you
>>>> should be able to see two more harmonic bands at around 3 khz and 2
>>>> khz for at least some of the calls. At 1 kHz things get messy
>>>> because of other things calling.
>>>>
>>>> In Sonic Visualizer, I could not find where to adjust the  
>>>> brightness
>>>> and contrast and FFT for the sonograms, and therefore could not  
>>>> get a
>>>> very clear result.
>>>>
>>>> Izotope RX gave a good result (but only very slightly better than
>>>> Raven Lite), i.e. just looking at the spectrogram window of the
>>>> original recording and adjusting the controls for clearest  
>>>> settings.
>>>>
>>>> You are right that normally it is the higher frequencies that are
>>>> attenuated by distance. In the case of the frog distress call
>>>> though, the strongest part of the call is not in the lowest
>>>> frequencies, but higher up, say above 3 kHz. So with Tom's call
>>>> being so faint in the first place, maybe the lower frequencies  
>>>> simply
>>>> did not pick up on the recording.
>>>>
>>>> Also, I don't know what other effects the mp3 format may have  
>>>> had on
>>>> the recording.
>>>>
>>>> cheers,
>>>>
>>>> Vicki
>>>>
>>>> On 04/12/2011, at 12:56 PM, Peter Shute wrote:
>>>>
>>>>> Interesting. I can see the same sonogram patterns using Raven and
>>>>> Sonic Visualiser using the track you just uploaded, but on the
>>>>> original and all other attempts at cleaning it up, the sub 4kHz
>>>>> bands aren't really visible. Even in yours, they're much fainter
>>>>> that those above 4.
>>>>>
>>>>> I agree it looks like a good match, and a very likely one too,
>>>>> given the location, but I'm wary of something that's completely
>>>>> invisible on the original.
>>>>>
>>>>> Sonograms are a new thing to me, so I'm right out of my depth  
>>>>> here.
>>>>> Do you think the distance and reverb can explain why the lower
>>>>> harmonic bands are fainter? I would have thought higher  
>>>>> frequencies
>>>>> would be attentuated by distance more than lower ones (but I'm not
>>>>> sure about that).
>>>>>
>>>>> Or perhaps they're just almost completely masked by the frog
>>>>> chorus, and would have to be fainter once that's removed. On  
>>>>> closer
>>>>> inspection, I can see a faint band around 3kHz on the original in
>>>>> a couple of spots (eg 28s), but I just couldn't say below that.
>>>>>
>>>>> Peter Shute
>>>>>
>>>>> ________________________________
>>>>> From: <naturerecordists%
>>>>> 40yahoogroups.com><naturerecordists%
>>>>> 40yahoogroups.com>
>>>>> <naturerecordists%
>>>>> 40yahoogroups.com><naturerecordists%
>>>>> 40yahoogroups.com>] On Behalf Of vickipowys
>>>>> <vickipowys%
>>>>> 40skymesh.com.au><vickipowys%40skymesh.com.au>]
>>>>> Sent: Sunday, 4 December 2011 11:25 AM
>>>>> To: <naturerecordists%
>>>>> 40yahoogroups.com><naturerecordists%
>>>>> 40yahoogroups.com>
>>>>> Subject: Re: [Nature Recordists] Re: Advice needed for cleaning up
>>>>> this recording
>>>>>
>>>>>
>>>>>
>>>>> Peter,
>>>>>
>>>>> I'm sorry you've given up on the mystery call. Here is one last
>>>>> attempt on my part to convince you the mystery call really is the
>>>>> distress call of a Green Tree Frog.
>>>>>
>>>>> I've selected just a short side-by-side comparison, using the
>>>>> clearest part of Tom's recording that I could find. I've also
>>>>> presented the recordings at half speed, which is always useful  
>>>>> for a
>>>>> listening test.
>>>>>
>>>>> This is the soundcloud link:
>>>>>
>>>>> http://snd.sc/ticMjy
>>>>>
>>>>> I've included a Raven sonogram that shows how the harmonics,
>>>>> although
>>>>> faint, do extend well below 4 kHz (you thought they did not).
>>>>>
>>>>> I did some broad band noise reduction on Tom's original recording
>>>>> using RX, and removed the prominent insect call.
>>>>>
>>>>> cheers,
>>>>>
>>>>> Vicki
>>>>>
>>>>> On 03/12/2011, at 7:26 PM, Peter Shute wrote:
>>>>>
>>>>>> Thanks everyone for your attempts at cleaning up this recording.
>>>>>> We've given up on identifying the call for now. I assume it  
>>>>>> must be
>>>>>> a lesser known call that we have no samples of for comparison. We
>>>>>> had quite a few suggestions that sounded similar, but nothing  
>>>>>> with
>>>>>> a matching sonogram.
>>>>>>
>>>>>> Now I just have to try to understand the steps you all took so I
>>>>>> can try for myself next time.
>>>>>>
>>>>>> Peter Shute
>>>>>>
>>>>
>>>>
>>
>
>
>
>
> ------------------------------------
>
> "While a picture is worth a thousand words, a
> sound is worth a thousand pictures." R. Murray Schafer via Bernie  
> Krause.
>
> Yahoo! Groups Links
>
>
>







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