cycles and beats

[Jim]

Dear Bill and Pat:

Cycles per second are the same as Frequecies or Hz.  Beats are caused
by the difference between two frequencies.  A Beat Frequency Oscillator
will use two very high frequencies beyond aural range to produce a tone
in our aural range by tuning one of the high frequencies to a slightly
different frequency.  A very common example of beats can be heard when
one plays the A string and the E string of a violin together. A difference
tone can be heard which is one octave below the A string.  This is a
Beat frequency which is heard as a tone.  The kind of beats with which we
as piano technicians are concerned are much slower and are heard as
undulations or wavers of the pitch where the two frequencies are
relatively close.

If the 3th partial (or theoretical harmonic) of A=220 and the 2nd partial
of E=330 are isolated and sounded together there will be 0.0 bps (beats
per second). This would be expressed as 660 - 660 = 0.0  However if the
E is tuned to equal temperament at 329.627, then the second partial of E
would be 659.254. Now there is a difference of 660 - 659.254 = 0.746. In
this case we would hear a beat frequency of approx .75 or 1 1/2 beats
every 2 seconds or a total of 3 beats in 4 seconds.  Piano tuners utilize
this phenomenon to gauge how accurately they are tuning equal tempered
scales.

Jim Coleman, Sr.

On Thu, 6 Feb 1997, BILL &PAT HOPKINS wrote:

> Are cycles per second and beats per second the same thing?
> Please explain.  Thanks
>
> Cyberpod@esslink.com
>
>