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Re: Scientific analysis and Mini Disc's

Subject: Re: Scientific analysis and Mini Disc's
From: Walter Knapp <>
Date: Sun, 25 Jul 2004 14:21:10 -0400
From: "S.P.Vijayakumar" <>

> 
> Friends,
> I need a bit a guidance on the following.
> I have decided to buy a Marantz PMD 222 system for recording frog 
> calls, that will be latter used for scientific description and 
> analysis. Much of my work is in rainforets. Before buying this, can 
> you advice whether its appropriate to buy this recording unit when 
> people are switching to Mini Discs, which appears to be relatively 
> less expensive.But i have seen many comments in the web regarding 
> effects of the compression technology thats used in MD, making 
> recordings not suitable for any scientific purpose.

I've been recording frogs in scientific studies for 8 years now. The 
first 5 was the Georgia Herp Atlas, a survey of the entire state of 
Georgia for frogs. Since then I've continued the same work in a less 
formal way. For the Georgia Herp Atlas I recorded frogs at over 800 
sites, for several thousand individual species records. I'm the only 
person to have recorded the calls of all 31 species in Georgia. And my 
work by itself provided more distribution data on frogs in Georgia than 
all the bodies in bottles of all time.

All of this on minidisc. At first with a Sony MZ-R30, of which I wore 
down two of them (the tiny switches under the tiny buttons are 
vulnerable, though replaceable). Then moved up to the HHb portadisc, not 
so much because the Sony could not do the science, but for better 
features like human sized keys, bug light yellow lighted display (you'll 
find out the value of that recording frogs) and a common size battery 
system. And as I wanted to get into recording quality listening CDs and 
the Portadisc had much better electronics.

Since the end of the Herp Atlas we have also edited some of my survey 
recordings into a combination ID and listening CD, which is well liked. 
The first year of sales will be close to 3000 copies. All benefiting the 
DNR's research and education effort.

I moved to minidisc from cassette 8 years ago primarily to avoid the 
continual headaches I had with cassette in the heat and humidity of 
Georgia. I would not have moved to any other magnetic tape system at the 
time, so choose minidisc, primarily for it's very reliable optical disc 
system. It's worked much better than cassette. Extremely reliable. I 
never even have needed to clean the mechanism on any of the minidisc 
equipment I own, it's never failed me. I not only do my nature recording 
on minidisc, but all my cars have minidisc for music. I listen to just 
about every type of music, except most of rock and it's variants.

So, for those that say it's not suitable for any scientific purpose, I 
say not to the herps folks of Georgia. None of the scientists I work 
with have ever questioned the use of minidisc, on the contrary they 
consider it a superior system. To them all that counts is the quality of 
the recording, not the mechanism. They judge the quality based on being 
expert field biologists extremely familiar with the calls in the wild. 
Some of the field biologists I work with are still using cassette, field 
biology is one of the poverty stricken fields. But, I'm quite sure given 
the chance every one of those would switch to what I'm using in a flash.

Georgia's frogs range from 200Hz to about 8kHz in frequency range. I 
doubt you will be recording much higher, as Georgia's frogs include the 
Little Grass Frog, the smallest frog in north america and barely larger 
than smallest in the world. They hold the high frequency end here, 
sounding like insect calls to the uninitiated.

In addition to the contribution of my work to herps, the Georgia 
breeding bird atlas group picked through my recordings to pick out the 
incidental bird records for their work. Without being involved in that 
work I hold some county records for birds in Georgia too. If there was a 
insect survey going on they'd find plenty too.

As far as your scientific use, it depends. While I don't doubt that 
minidisc can provide the recordings needed, that's not the whole story. 
If for instance you are planning on publishing in the peer reviewed 
bioacoustics journals it probably won't do, but neither will the PMD 222 
or your mic choices. Those folks make a religion out of a few very 
expensive measuring systems. And close their minds to anything else. You 
will be into spending a huge sum on fairly impractical gear to keep them 
happy.

So, you probably want to look at that end, and have to live with what's 
dictated. Good luck finding something suitable for field recording if 
dealing with the worst of those folks. If you are lucky enough to deal 
with real field biologists you should be fine with either choice. I'm a 
retired field biologist. I've read a great many scientific papers on 
frogcalls, and seen what was in their papers in the way of sonograms and 
so on. I have seen nothing that could not be done by minidisc. It's more 
a attitude problem than a equipment one.

I don't know as I'd say people are just in the process of switching to 
minidisc. Maybe in some groups, but for nature recording as a whole 
cassette has been long passed by. Any magnetic tape system is or soon 
will be history. I'm sure many will continue to use the tape equipment 
they have as long as it runs ok, but it won't be considered a good 
choice for new equipment.

There was a recent discussion in the group on ATRAC. I don't care to 
engage in that silliness anymore, and have been that way for years so 
won't comment here. If you write me privately I'll be happy to discuss 
my experience with it. Or whatever analysis you are trying to do on 
frogs, I do a lot of that, primarily sonogram work.

Glad to see another frog recordist in this sea of feathered dinosaur 
recordists.

Walt






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