"Batbox Baton" sound recording - technical help needed

[AshLee]

I'm totally new to bat detectors. I have had a "Batbox Baton" sitting around accumulating dust for a while now. Then, the first time I used it, I immediately realised that I would need to record and analyze to get the best from it (it works by frequency division). Time, money and energy were then spent getting it to work with a dictaphone. Everything is now wonderful...

BUT

...when connected to the dictaphone using a jack lead you cannot hear what's going on! I didn't think this would be a problem, until, whilst taking a few recordings for the first time last night, my partner and I realised just how short bat calls are . And infrequent . We don't have a laptop to use. When I buy one, it'll be too good to be coming out into the field with me. That's just a recipe for a disaster.

In the end we used the in-built mike of the dictaphone (basically, we took the cable out and held the two instruments together). I still have to see if I can get the software to work with the material I have, so I don't know if it's any good.

But surely there is something smaller than a laptop that will allow you to hear the bat calls when recording, and only record the interesting bits.

A splitter with an ear piece or a speaker didn't work. The output from the detector cannot be monitored with this type of device.

Has anybody solved this sort of problem with a neat, practical solution that doesn't involve a laptop?

Thanks,

Ash

[The Woodman]

Good morning Ashlee

I use a Baton as a back up or additional survey detector. It comes with its own dedicated analysis software Batscan 9 on CD (which also works well with the Duet).

As you will know the Baton is a very simple non-tuneable FD detector. If you want to record ultrasound for analysis with Batscan you will need a digital recording device capable of .WAV files. People do use cheap end mp3 players and Pettersons software Batsound. There are other non dedicated programmes out there - get signed up to BCT's forum and see what David Lee recommends.

The output socket will not work with headphones and the speaker will automatically disconnect when an output jack is used. If you need to monitor your recording, as far as I know the only way to do is using headphones from the output socket on the recording device (if it has one).

I use Olympus LS10 these days which I've reviewed in the Review section. The display also tells me the dB level of the recording which is useful when not using headphones. Any recorder used for sound analysis must have certain qualities and the required tech spec is contained in a useful doc published by the BCT. If you cannot find it on their website, PM me an email a/d and I'll send it to you.

Your recordings taken from speaker to mike cannot be used for analysis. I know you haven't got a laptop but it is possible to watch real time analysis- sonograms and oscillograms - using the software on a laptop. It should be possible to do this with a PDA as well. To answer your question, the only way to hear the bat call using a Baton is to use a recording device with a headphone output socket.

Hopefully I've answered a few Q's, get back to me if I can be of further assistance.

[The Woodman]

This is the sort of thing Batscan can do, in this case a common pipistrelle call sequence.

The two horizontal frequency markers are set at 45 and 55 kHz.



Some of the louder calls are clipped but identifiable as a common pip.

[AshLee]

Woody,

Your advice (as always ) is very welcome. Excellent stuff.

Although I'm mildly suicidal that all the data from my recordings last night is wasted I have decided to live and learn.

I shall investigate further....

Ash

[AshLee]

PS Sorry to hear about the shootings up your way yesterday. I hope you and yours weren't affected.

[The Woodman]

OK thanks AshLee, fortunately we're a few miles further south. There's a numb atmosphere about today, to say people are shocked is an understatement.

Have another go at recording tonight. Get the recorder ready and use the Baton without the connecting lead plugged in. As soon as you hear a bat over the loudspeaker, plug in and record. Keep each recording as short as possible as it makes analysis easier - use "Scan File" on Batsound.

Can you tell me what device you use to record on - make and model?

Let us know how you get on.

p.s. This is the article from BCT you might find interesting

http://www.bats.org.uk/publications_...ctors_2008.pdf

[AshLee]

Hiya,

Will keep you posted. (I'll have to find the manual ).

I was in ancient woods in Hertfordshire when I did the recordings. I can't return for more than a week, I think . Unfortunately there are no longer any bats in our garden (but plants are growing to replace the neighbour's plants that were uprooted as we speak). I'll be out again as soon as I can.

But I just wanted to say thanks very much for that link! And the advice on how to get the recording until I can work out a better system. Much appreciated!

Ash

[Phil Eyden]

Hi,

Not exactly the same problem as AshLee but I didn't want to start a new Batbox Baton thread.

I am completely new to bat detectors too and have only tried it out twice. The following is an image uploaded this evening directly from the Baton to the laptop via the line-in and recorded via Batscan.

I think it shows a pipistrelle as the chirp is bouncing along at around 45mhz.

The Baton generates a lot of hissy white noise and this may account for the noisy chart - it certainly doesn't resemble the optimum settings as per the guide no matter how much I fiddle with the microphone settings and amplitude levels. My questions are, is there anyway of cleaning up the sound, or do I have the settings wrong? Also, can any extra info be gleaned from the Baton's recordings, or is the following image a fair representation of a typical recording?

Whether or not I have the settings right, the Baton is incredibly good fun!

Thank you!

Phil

[The Woodman]

Hi Phil

There's coupe of things to consider.

Does your recorder record .wav files? I'm pretty sure Batscan is set up for .wav.

You might try reducing the noise slightly by pulling in the oscillogram - along the top - by moving the vertical slider button on the right edge downward so that the blue graph line is contained in the white area.

When you highlight a single call and zoom into it, can you see the inverted p for pipistrelle?

I find it useful to set the two frequency markers at 45 and 55 kHz.

You've also got 12 pulses per second which is the same as my example.

The sonogram is pretty noisy but you've got repetition rate and the oportunity to look at the individual signature. If you can put it all together with flight characteristics and habitat you should be able to get to a reasonable conclusion!

[AshLee]

Originally Posted by The Woodman

Have another go at recording tonight. Get the recorder ready and use the Baton without the connecting lead plugged in. As soon as you hear a bat over the loudspeaker, plug in and record. Keep each recording as short as possible as it makes analysis easier - use "Scan File" on Batsound.

Can you tell me what device you use to record on - make and model?

Let us know how you get on.

Hi Woodman (for some reason I nearly called you Batman )

The device is a Grundig Digta.

One MAJOR concern is that when I plug the Batscan directly into the sound card of a PC, the range of frequencies is up to 200 kHz or more. When sound is recorded onto the Grundig and then data transferred from there, its maximum is only just over 50 kHz. The Horseshoe bats (? I think ?) have a higher freq. call, so would this device exclude much of their call?

I was testing the device with an ultrasonic Cat scarer, and I can see what you mean about the difference between data obtained using the jack lead, or the mike. It is very different.

I have another question. I can obtain the peak frequency quite easily. But is this the same as the frequency that you read about, with the Hetrerodyne type Bat detectors? I will no doubt, with the correct recording device, get lots of data. But the info. that comes with the Batscan so far has described the Heterodyne method (although I have an unopened CD yet, so it might be in that).

Thanks,

Ash