Vocalist.org archive


From:  Martyn Clark <martyn@v...>
Date:  Tue Sep 5, 2000  10:40 am
Subject:  Tako's vocal clip, and Source of frequencies was:Falsetto Recognition


Tako, Reg, Kevin et al,

> Is the chap that was research assistant to Ingo Titze still on the list ?

Hmmm... yes, I am. Have been rather too busy to contribute for the last
while.. and it doesn't look as though things are getting any less busy.

Tako's vocal clip.....
>At the beginning and end of the clip, I am singing in "chest". In the
>middle of the clip, I am singing in "head". Notice that when I am singing
>in "chest" in the 200 Hz range, the formant range (for me, 2800-4000Hz) is
>heavily populated by the 13-20th partials.


What I hear in this clip, and see in the spectrogram are two things:

1) A signal which is not good enough for analysis (signal to noise ratio
high, recorded in an echoey environment or with reverb added, and some
clpping taking place at some stage in the process). To get quality
answers, you need quality equipment. The noise in the background looks
like a combination of general equipment noise, and left-overs from the
echo. Nothing more. It could also be a compression effect if you are
compressing the audio at all (like recording on consumer MiniDisc). I
don't think that from this recording anything can be said about the
vocal tract non-linear noise generation ideas... Most healthy voices do
not have much noise in them at all (ie Harmonics to noise levels of
16-20 dB for classical singing in mid-range, and up to 22 dB at high
pitches). The noise components generally seem to come from the vocal
folds themselves - when we see worse figures in the clinic, they can
generally be attributed to thickened mucosal layers of the larynx (ie
pathology or swelling). We use Harmonics to noise measurement as a
routine quick vocal health check for singers particularly. Using our
analysis package (which is not very reliable on such short segments, I
get a Normalised Noise Energy of -6dB. That's the recording.

2) A normal countertenor arpeggio, shifting from chest into a rich
head-type resonance. The shift in resonance is accompanied by an
increase in the level of sound, which alters the visibility of the
higher harmonics (particularly in the 4 middle notes in the arpeggio).

3) A relatively low level of "singer's formant" energy (measured as the
ratio of energy above 2500 to the energy below). From the recording, the
ratio is about 29% - about 10 percent below what we expect for
classically trained singers. This is going to be the case with a ligter
countertenor production, and explains why there is not much energy there
in the spectrogram. With the quality of the recording, however, none of
these figures can be overly trusted. We generally do our analysis
recordings using Neumann microphones, outboard pre-amplifiers, and
ensuring that background noise is at a minimum.


I prefer to think of the "singer's formant" as being a combination of
things. In fact, I would challenge anyone to state that it is NOT due to
a combination of things:

-> good, fast vocal fold closure will increase the energy in the higher
harmonics. The sharper the closure and the louder the sound, the more
energy there will be up in the higher partial regions.

-> appropriate vowel tuning will maximise energy transfer through the
vocal tract. Without correct tuning for each vowel, you are fighting a
losing impedance battle (especially going though the second passagio)

-> extra modifications (especially of the epi-laryngeal spaces) will
favour the brightness created at the vocal folds, and help to develop
that ring.

-> careful balancing of the tongue position to avoid LOW+BACK will help
the ring to resonate, and also simultaneously give warmth to the sound.

Don't have time for any more comment! Sorry.

Martyn Clark
Edinburgh Voice Centre
VCard
Martyn Clark <>

Director
Edinburgh Voice Centre

45 Newhaven Main Street
Edinburgh

EH6 4NQ
Scotland

Cell: +44 (0)7974 083 197
Fax: +44 (0)7970 796 321
Home: +44 (0)131 552 8013
Work: +44 (0)7974 083 197


  Replies Name/Email Yahoo! ID Date Size
3985 Re: Tako's vocal clip, and Source of frequencies Kevin Hollis   Tue  9/5/2000   2 KB
4004 Re: Tako's vocal clip, and Source of frequencies Tako Oda   Tue  9/5/2000   4 KB
4011 Re: Tako's vocal clip, and Source of frequencies Lloyd W. Hanson   Wed  9/6/2000   2 KB
4013 Re: Tako's vocal clip, and Source of frequencies Reg Boyle   Wed  9/6/2000   4 KB

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