ipod recording

[Susan Penfield]

Thanks for this, Natasha -- point well taken. The background noise issue is
certainly something
that field linguists always have to deal with and consider.  The bottom
line, for endangered language
work at least, is still that any recording is better than none. I wouldn't
want anyone to wait to have the
perfect equipment while letting the perfect opportunity slip away.

S.


On 7/24/07, Natasha L Warner <nwarner at u.arizona.edu> wrote:
>
> Hi,
>
> before we totally write off all compressed data that already exists, let's
> think twice.  Sure, if you're choosing at the beginning of a project, it's
> probably far better to just record uncompressed in the first place.  But
> if data exists that was recorded in a compressed format, that doesn't make
> it useless, it depends greatly on what you're going to be measuring.
> Pitch, for example, is extremely robust, even under atrocious recording
> conditions and with poor equipment.  One of the few things that will make
> pitch unmeasurable is overlapping voices (or other periodic sound sources)
> where the one you're trying to measure is not substantially louder than
> the others.  But considering that you can measure pitch even with shocking
> amounts of background noise, or an extremely clipped signal, I'd be
> surprised if you couldn't measure it pretty reliably on mp3 data.  On the
> other hand, if you want to measure voice quality (creaky voice, breathy
> voice, etc.), then you need to know that you have a really reliable
> recording that didn't mess with the spectral tilt.  But at that point,
> position of the mic relative to the mouth is also going to be pretty
> important.
>
> A few years ago when the compression at issue was minidiscs, I
> heard that a few phoneticians, including Ian Maddieson, did a test of
> compressed vs. uncompressed recordings and couldn't find a difference in
> any part of the signal they were interested in.  They concluded the
> compression wasn't so bad.  Of course, I'd rather know I have uncompressed
> data so I just don't have to worry about it.  But given a choice of using
> existing compressed data or starting over, I would look at the signal and
> see what looked measurable and what didn't, keeping the compression in
> mind.
>
> Also, it's worth considering that in many field recording situations, the
> background noise (whether it's airplanes, construction noise, chickens,
> kids, crickets, refrigerator hum, a college cafeteria, or a preschool
> setting--I've run into all of these at least indirectly, for acoustic
> phonetics work) is going to contribute a whole lot more problems to the
> signal than the compression creates.  And sometimes we do work with data
> collected over the phone, which limits the signal a lot more than
> compression does.  So my personal approach would be to use a reasonably
> good headmounted mic, get it as close to the speaker's mouth as possible,
> make sure any other noise sources are far further from the mic than the
> speaker's mouth is, and record uncompressed if possible.  It would also be
> nice to have a clearer understanding than I do at this point of just what
> we lose during the compression.
>
> Thanks for the discussion, everyone,
>
> Natasha Warner
>
>
> *******************************************************************************
> Natasha Warner
> Associate Professor, Department of Linguistics
> University of Arizona
> PO Box 210028
> Tucson, AZ 85721-0028
>



-- 
____________________________________________________________
Susan D. Penfield, Ph.D.

Associate Director, Center for Educational Resources in Culture, Language
and Literacy (CERCLL)
Department of English (Primary)
American Indian Language Development Institute (AILDI)
Second Language Acquisition & Teaching Ph.D. Program (SLAT)
Department of Language,Reading and Culture
Department of Linguistics
The Southwest Center (Research)
Phone for messages: (520) 621-1836


"Every language is an old-growth forest of the mind, a watershed of thought,
an ecosystem of spiritual possibilities."

                                                          Wade Davis...(on a
Starbucks cup...)
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