Hello BirdChatters and EBN-ers,
I got more than 20 reactions on my question if MINIDISC is good for bird sound recording. Thank you all.
Most reactions fall in two groups:
A. Consists of professional (or nearly so) ornithologists. They have sincere objections against the minidisc technique, because of the digital compression during the recording. During this minimizing of the size of the recorded sound some things are lost, and for scientific analysis of the sound characteristics these recordings are outlawed.
B. Consists of birders who don't use their recordings for that sort of scientific analysis. They make recordings with minidisc for some time now (up to some years), and are enthousiastic about the quality and about the ease of access to specific recordings.
Before going into the details of these two opinions, I should mention a third opinion first. Compression of the recorded sound is only necessary because of disk space limitations: if minidisc would not use compression, then you could only store 15 minutes of sound in stead of 74. However, the technological developments in disk storage are fast, and it may be expected that in a few years there is no more need for (quality-loss) compression during recording. Then minidisc would only be a transient technique of the late nineties....
The compression technique is called ATRAC. It would assume that what you are recording is either music or human voice. So it would skip all sorts of noises that you don't really need when you playback the recorded sound. Now the opinions differ if you can hear this loss of detail in bird sound recordings. Some say they can hear it, others say they cannot, or scarcely hear it. So I have to find out the measure that I can hear it myself, and I have to find (actually asked) original minidisc recordings of critical bird sounds. It is important that these recordings be unfiltered afterwards, because filtering gives distortions that can interfere with quality aspects of the original minidisc recording.
It would be nice if somebody would place examples of unaltered minidisc bird sound recordings on a web site, as .wav files. Would be even nicer when for comparison cassette field recordings of the same sounds would be added.
Other questions in my RFI were about the ease of use, and the durability. The (Sony) minidisc recorder has easy direct access to recorded samples. On the other hand, they have made the recorder so tiny that it is not always easy to find the buttons when recording in the field. The durability in difficult outdoor circumstances proves to be good (the reports range from deserts to rainforests), and probably far better than the DAT-recorder (digital audio tape, which does not use compression). The discs themselves can also stand some outdoor handling, as they are cased in hard plastic.
The fact that you have direct access to tracks on a minidisc is regarded as a great thing when using prepared recordings in the field, for identification of a sound you hear. You can store 199 numbered tracks. The same holds of course when in the field you want to go back to an earlier recording and see if it's the same species as the one you hear now ("that 25th antbird"). By the way, computer handling of the minidisc recordings still involves an analogous stage in between the digital of the minidisc and the digital (.wav) of the computer.
Sony and Sharp are the only minidisc field recorders that I know of, and in the mails specific reference is only made to the Sony MZ-R30. This one is being replaced now by the even smaller R50, which is (according to info on www.minidisc.org) better for field recording because the batteries last longer, and the shock-proof memory is 40 in stead of 10 seconds. On that same minidisc website there is a comparison between the Sony and the Sharp. For our purposes an important drawback of the Sharp is that it is reported to have a delay (of seconds even) before it really starts recording.
Many people stress that a good microphone is at least as important as the recording device. The speaker, for playback in the field, need not be sophisticated.
Well, I know a lot more about minidisc now, but as stated above, first I want to hear some examples of original, unfiltered recordings before deciding for this (transient?) technique, or for one of the better cassette recorders.
John
John van der Woude Kudelstaart (near Amsterdam), The Netherlands
jvanderw@worldonline.nl
John's birding trip reports, mainly Neotropics, with many photos of sites
From Mort and Phyllis Isler
To Multiple recipients of list NEOORN-L
About a year and a half ago, NEOORN had an excellent back and forth discussion
about Minidisks, but a number of you may not have been enrolled at that time,
and Charles Duncan's quote from the Budney and Grotke paper belittling
Minidiscs requires a renewed response.
The key questions is whether audio engineer Grotke's conclusions about
deficiencies in the Minidisk are relevant to its application to recording and
using avian vocalizations. Our conclusion, after years of using Minidiscs, is
that his conclusions are not relevant. We have also put Nagra, cassette, and
DAT recordings directly into CANARY (the Cornell Bioacoustics Workstation) and
compared these with the same recordings put onto Minidisks and then into
CANARY. We have seen no differences in the displays (e.g. spectrograms) and
because we measure vocal characteristics from displays, we can see no
difference in vocal measurements that we take. We have never found the
slightest evidence of sound distortion caused by the MD. With regard to the
question of using the MD in vocal analysis, as we pointed out a year and a
half ago, there is a perfect analogy in the quality of calipers to measure
bird skins. $200 electronic calipers undoubtedly produce larger errors than
$4000 calipers needed to measure fine machine parts, but that error is totally
meaningless given the human error in making the relatively inexact (compared
to a machine part) measurements of birds. Judgements about an instrument's
degree of precision should be relevant to the scientific task at hand.
With all due respect to the concern and professional competence of the
authors, we believe the Budney and Grotke's findings are immaterial to
recording, listening, learning, using the recordings for playback, and making
avian inventories (following Parker 1991 [Auk108443-444]), which are the uses
most of you will make of recordings, as well as to the quantitative analysis
of avian vocalizations. Minidisks are a superb medium for the individual (not
necessarily institutional archives like LNS) to maintain and access a
recording inventory. Accompanied by a database to locate the disc and cut
number of a recording, MDs can produce a recording almost instantly.
Moreover, individual notes within a recording can be accurately pinpointed and
accessed immediately. Having worked with Nagras, cassettes, and DATs, we find
there is no comparison in the opportunities to learn and analyze bird
vocalizations that MDs bring.
We would add two notes regarding the limitations of our own experience.
First, we have been working with rather uncomplicated vocalizations of
suboscines in the 500 to 8000 Hertz range, and, second, we use the MD to
archive and analyze and not to make field recordings.
14 February 1999
Dear NEOORNers
I've read with interest the recent correspondence about mindisc and
other recording options. I feel its time I entered the fray to defend
and promote minidisc as an EXCELLENT and cheap system for field use. I
should perhaps start by explaining that I am a professional bird tour
leader for Sunbird (UK) and Wings (USA) and have been leading tours full
time for those companies for nearly 20 years. I have been making field
recordings of birds and using playback extensively on my tours since
1982. I have NEVER owned a TCM-5000. In the early days I used Sony
Walkman professionals (WMD-3 and WMD-6) with an external speaker.
For the last ten years I have been leading many of my tours with my
partner Judy Davis, and all credit must go to her for spotting the
amazing advantages that minidisc would give us for playback right from
the moment Sony launched it. For the last five years we have been using
minidisc for playback and for the last three for field recordings. I
used DAT for a while, but gave up due to the hopeless problems with
battery consumption and the delay with starting the machine recording.
Firstly, I should say that I agree wholeheartedly with Mort and Phyllis.
I have never been aware of any distortion in any MD recording and I've
seen no proof that sonograms made from minidisc look any different from
those made from analog recordings or DAT. I've corresponded and
discussed this at length with Richard Ranft at the NSA in London and
while he was initially reluctant to archive minidisc recordings the NSA
have now purchased MD equipment and are willing to accept them. Richard
agrees that he can find no meaningful or practical difference with
minidisc recordings. I've also challenged Greg Budney to come up with
much greater proof than that given in the Ted Parker memorial volume
article, but so far nothing has been forthcoming from LNS. I'm no
technician, and it may be that there are minor and subtle differences in
the recordings which really sophisticated analysis methods could detect,
but as Mort and Phyllis have indicated, for all practical purposes such
differences are irrelevant.
John Arvin said that the smaller MD machines aren't practical in the
field because they don't have built in speakers and stated that this
makes them 'cumbersome and inefficient'. As a tour leader who has NEVER
used a machine with a built-in speaker I beg to differ. I've always
used external speakers. We make a case with a shoulder strap for the
speaker. The speaker is turned on its side, and we mount TWO machines
side by side on top (in early years two WMD-3s, now two minidisc
machines). One machine is used for playback the other for new
recordings, so we seldom have to change tapes or discs in the field. We
use Sennheiser mics and when not in use attach these to the bottom of
the speaker case with a couple poppered loops. The whole set up weighs
about the same as a TCM-5000 and is VERY practical in the field..
For playback the advantages are outstanding
1. Up to 264 species on one disc.
2. Almost instant and precise access to any of them.
3. A repeat playback facility, so no need to wind back the tape.
4. Low battery consumption - during three months leading tours this
winter I have never had to change batteries in the field.
Having used tapes for playback in my Walkman professionals for nearly 15
years (and become fairly accomplished at it), I feel justified in saying
that I now regard using tapes for playback as Dark Age technology
compared to minidisc. All of the Sunbird leaders who use playback on
their tours changed over to minidisc between 1 and 3 years ago. This
includes Richard Bashford, Judy Davis, Tom Gullick, Paul Holt, Steve
Rooke and me.
Recording is more controversial, primarily because of the reservations
expressed by Greg and Bob at Cornell. Much correspondence has appeared
in print on this subject in recent issues of Wildlife Sound, the journal
of the Wildlife Sound Recording Society. I would guess that few of the
subscribers to NEOORN have access to this journal and obviously I have
no way of adding the relevant papers in to this contribution, but I
refer those who want to know more to that journal. Several members of
the society are firm proponents of minidisc and have thrown out similar
challenges in print to the sound collection archivists to prove that
there are any practical shortcomings to MD recordings. As far as I am
aware, no one has been able to.
One practical problem concerning using minidisc for recording in the
field is that the input on the small Sony machines doesn't match the
output of the Sennheiser mics that most of us use (ME-66's in our case).
This results in rather quiet recordings, which for instant playback in
the field can be a problem. We solved this by having matching
transformers made for us (arranged through Duncan Macdonald at
Wildsounds in Norfolk, UK). This increased the volume of the recording
by about 20% to a perfectly acceptable level.
So, for recording in the field the advantages are
1. No tape hiss.
2. Much greater frequency range than most other systems.
3. 64 minutes of recording space per disc in stereo mode or 128 minutes
of recording space in mono.
4. The ability to let the machine record for up to 128 minutes while
you wait for the bird to call (AND then to be able to delete all the
unwanted minutes of silence straight away - i.e. edit your recording -
and use all of that space again immediately).
5. Because of the amount of space on each disc, there is normally no
need to open the machine to change discs in the field.
6. Low battery consumption (especially compared to DAT).
7. No problems with humidity (at least none experienced by us - and
most of our tours are in the Neotropics).
8. The ability to leave the machine in recording mode with the pause on
for long periods without excessive battery consumption so as to be able
to record at the press of one button.
9. The machines are now VERY cheap. The standard portable recording
model can be purchased in London for around UKPounds 150-170 ($250-280).
Some drawbacks are as follows
1. Some people find the controls rather small for their fingers.
2. The manual recording level can't be adjusted while the machine is
running. It is necessary to press the pause button, alter the recording
level, then press the pause button again. With practice this isn't a
major problem.
3. Impossible to repair in the field, so we carry a spare machine each,
but as they are so small this is no big deal.
I should finish by mentioning that the 1998 Wildlife Sound Recording
Society's annual competition winning entry was recorded and mastered on
one small cheap minidisc machine. There were about 50 entries and the
judges weren't told anything about the recording methods used and judged
solely on quality of the recording and interest of the presentation.
The recordist was Danny Alder - and his winning entry was superb!
Hope this helps to convert some of you over to the most exciting
innovation in sound recording in recent years.
David Fisher
From David Fisher