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Re: two sine tones simultaneously within one critical band

To: AUDITORY@xxxxxxxxxxxxxxx
Subject: Re: two sine tones simultaneously within one critical band
From: Piotr Majdak <piotr.majdak@xxxxxxxxxx>
Date: Fri, 7 Oct 2005 16:32:12 +0200
Delivery-date: Fri Oct 7 10:35:54 2005
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Bob Masta wrote:

> I am completely at a loss to understand how you arrived
> at your last formula.  It appears that you have not simply
> added the pressure waves, but multiplied them.


cos(2pi*t) * cos(100 * 2pi*t) = cos(99*2pi*t) + cos(101*2pi*t)

This can be derived using:

cos(x1)*cos(x2) = 1/2*cos(x1-x2) + 1/2*cos(x1+x2)

Another explanation can be: two frequencies (99Hz and 101Hz) can be seen as one absent carrier (100Hz) modulated with a modulator (1Hz).

br, Piotr Majdak


--
Piotr Majdak
Acoustic Research Institute
Austrian Academy of Sciences
Reichsratsstr. 17
A-1010 Wien
Tel.: +43-1-4277-29511
Fax: +43-1-4277-9296
E-Mail: piotr@xxxxxxxxxx
WWW: http://www.kfs.oeaw.ac.at

References:
- Re: two sine tones simultaneously within one critical band
  - From: Bob Masta
- Re: two sine tones simultaneously within one critical band
  - From: Bob Masta

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