Klarinet Archive - Posting 000235.txt from 1994/02

From: Cary Karp <nrm-karp@-----.SE>
Subj: Re: Diaphragm vibrato
Date: Thu, 17 Feb 1994 17:59:03 -0500

On Thu, 17 Feb 1994, Jay Heiser, wrote:

> You'd have to put a scope on it to really analyze what happens
> to the sound, but let me take a stab at what happens with flute
> vibrato:
>
> The speed of the air blowing over the tonehole does effect
> intonation. Creating pulses in the air flow then would cause
> minor pulses in pitch. I'd never really thought about it before,
> but I think that flute vibrato includes both pitch and volume change.

Using an oscilloscope confirms exactly what theory predicts. Flutes are
velocity controlled -- when you blow harder, pitch increases. Clarinets
are pressure controlled -- when you blow harder, loudness increases.
Diaphragm vibrato on a flute modulates velocity and therefore pitch.
Diaphragm vibrato on a clarinet modulates pressure and therefore
loudness.

It is entirely possible that embouchure adjustments applied simultaneously
with the diaphragm bouncing may cause secondary pitch changes on the
clarinet and secondary loudness changes on the flute.