Re: Pitch & fundamental frequency


Subject: Re: Pitch & fundamental frequency
From: Scott Lindroth (scott.lindroth@duke.edu)
Date: Tue Sep 06 2005 - 14:30:49 EDT


On Sep 6, 2005, at 1:18 PM, Dennis Bathory-Kitsz wrote:

> At 11:08 AM 9/6/05 -0400, Greg Eustace wrote:
>> I have heard of cases where the pitch of a pitched sound is not
>> characterized
>> by
>> the fundamental frequency. To reiterate, I am concerned only with
>> those
> sounds
>> having a discernable pitch which is not in obvious one-to-one
>> correspondence
>> with the fundamental. Can anyone elaborate on this, as it seems
>> counterintuitive
>> to me?
>
> By one-to-one, are you eliminating octaves?
>
> One anecdotal example of the missing fundamental or misperceived
> fundamental is the so-called "cambiata" voice of girls and boys just
> at the
> biological change. The octave in which the voice sounds is sometimes
> unclear, as it's rich with sounds that can suppress the apparent
> fundamental.
>
> I haven't examined this for at least 30 years, so I'm not sure if this
> is
> what you're asking, nor (since it predated any sound analysis tools at
> my
> disposal!) how the sound actually falls out in proportion of harmonics
> and
> masking of the fundamental.
>
> Dennis

My favorite experience with ambiguous octave location is an
orchestration mistake I once made with French horns. By placing the
horns in the high tenor register (concert G above middle C up a perfect
fifth to D a ninth above middle C), they "sounded" an octave higher
than trumpets playing the same fundamental frequencies. A similar
phenomenon occurred when the horns were playing in a comfortable
mid-range register (concert middle C up a fifth to G above middle C)
alternating with flutes and oboes playing the same figure an octave
higher. The impression was that the flutes and oboes were playing the
same fundamental frequencies as the horns, i.e,, there was not a clear
perception of registral ascent as the horns passed their figure off to
the woodwinds.

Of course, composers have known about this for a couple centuries, but
I had to learn the hard way. :)

SL



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