I wrote last week to find out about options for automated data
recorders. Here's a copy of my original e-mail, followed by some
observations and the responses I received:
"I am working to set up a pilot project that aims to deploy audio
equipment in remote locations to automatically record wildlife
vocalizations. The recorders need to be as inexpensive as possible,
weather proof, high storage capacity, battery operated, with
programmable timing, and pretty small / inconspicuous. The recording
quality needs to be sufficient for pattern recognition of
species-specific vocalizations (frogs, crickets/katydids, birds). We'd
like to be able to deploy these for up to two weeks at a time. I'm
aware of Cornell's "ARU"s, but it sounds like they are proprietary,
pricey, and only available for lease. I'm also aware of the Wildlife
Acoustics Song Meter, which I think would fit the bill for my project.
I have not been able to find any alternatives to the Song Meter system.
However, my contracting office is claiming that there are "lots" of
alternative vendors for similar systems. Is anyone on this list aware
of alternative systems available for purchase? Has anyone had good or
bad experiences with the Song Meter system or an alternative system?"
Thanks to all of the people who responded to my question! It turns out
that the Wildlife Acoustics system does currently seem to fill a
somewhat unique niche; there do not seem to be other recorders available
for a similar price, other than home-made systems (and part of the goal
of the project I'm working on is to compare home-made systems to more
professional equipment). However, it seems that there are a number of
groups actively developing recording systems, and this may change in the
next few years. Here are the responses that I received:
1) I have been occasionally helping and monitoring how Neil Boucher has been
doing with his new approach (software and off-the-shelf hardware). It gives
you another option to consider. They are using his system to find and
monitor rare parrots in Australia. Web site: www.soundid.net.
2) There are not many recorders that offer programmable recording times.
However, There are many digital audio recorders that utilize MP3 or WMA
compressed formats and can achieve long deployments. We have used a lot of
Zoom H2 recorders, which utilize SDHC flash cards for storage. The
recorders are less than $200, and a 32 gb SDHC card cost around $100. The
self noise on the internal microphones is about 25 dBA, which is decent. At
a 64 kbps MP3 rate this unit will give you 46 days of continuous recording.
These units provide higher quality recording options for other
applications, including a 4 channel mode (with internal microphones). Data
offload is USB 2.0. You will need to provide external power. The Zoom
consumes 248 mA at 2.45 volts (through the internal battery connectors), or
76 mA at 9v through the external connector (pin negative on the
connector!). If you want to go really inexpensive, some colleagues at
Zion NP have used
digital voice recorders to monitor for Mexican Spotted Owls (4gb, $25 ea,
much lower audio quality, lower power consumption). There are other
options between these extremes. There are several recorders that do
scheduled recording from internal FM
receivers and have external recording options, so a very small change to
firmware might give you exactly what you need. The trick would be getting
access to the development system, or perhaps implementing RockBox.
3) the Batcorder http://www.ecoobs.com/cnt-batcorder.html is a pretty
new piece of equipment which should meet most of your criteria. However,
it is especially designed and programmed to exclude all non-bat calls,
which makes it also rather pricey. I'm not sure whether the guys would
take out that functionality if you asked them.
4) AUSOMS-7, which stands for Automatic Underwater Sound Monitoring
System) is available. I have heard AUSOMS-15 (15 days recording time) is
on sale now.
For details, contact Dr. Tomy Shinke at SIT Co.Ltd.
5) My academic adviser has created a couple generations of small
programmable digital recorders for underwater (and terrestrial) use and
they are very good for long term deployments. I'm not sure what your
budget is, but they certainly will be capable of accomplishing
everything you listed. Here's a link to his website
6) We make an acoustic logger, storage up to several 100 GB drives (the
laptop size ones), fully programmable, sampling rates to 24 kHz, low
power, low noise. They are used in underwater acoustics but could easily
be set up for terrestrial work. They may be out of the price range but
if someone was to order many we could get them commercially produced
which would bring the price down. They sample (16 bit) rather than
continually collect data as we write to flash card (power cheap) then
when this is near full boot up the hard disk and write to this (power
hungry). They are fully programmable (sample rates, schedules, etc) via
any PC comms package (ie. hyperterminal). As an example on power 48 D
sized alkaline batteries, 58 GB drive, gives us 10 months of recording
at 6 kHz sample rate, 200 s every 15 minutes. The units are well proven.
See www.cmst.curtin.edu.au for the loggers, although this is a little
out of date. If there was interest we could look at getting them
commercially made - we are a research group within a Uni, not a
7) Did you ever find out better systems that the WA Song Meter. I have
used them and will be glad to help with problem. See
http://www.real.msu.edu for my acoustic observatory.