Re: Difference Tones

[Chen-gia TSAI <gia@xxxxxxxx>]

In the CD of Ernst Terhardt's book 'Akustische Kommunikation' (1998, Springer) I heard the combination tones for the fist time.
There are two pure tones in the sixth track.
f1=1000 Hz; f2 varies continuously from 1200 Hz to 1600 Hz, then back to 1200 Hz.
I can hear the combination tones with frequencies 2*f1-f2 and f2-f1.

In a similar way, I produced audible combination tones with two flutes. I played a flute tone with constant frequency f2=1500 Hz. My teacher played a lower flute tone whose frequency f1 varied continuously from 1281 Hz to 1150 Hz, then back to 1281 Hz.
The difference tone f2-f1 was audible.

The flute is optimal for this experiment in that the pitch can be modified by varying the blowing angle.

Chen-Gia Tsai
gia@snafu.de