The international tuning standard for musical instruments is

The international tuning standard for musical instruments is “A” above middle C” at a frequency of 440Hz. Does it mean that it is a 440Hz square wave, which is the signal in a periodic pulse signal with a 50% duty cycle?

Solution

The standard pitch 440Hz (A4 note) is definetly a 50% duty cycle signal but it is not square wave rather it is a sine wave.

All notes are generated using the sinusoidal signals

MATLAB CODE :

fs = 44100; % sampling frequency
t = 0:1/fs:5; % time vector for duration 5 seconds
f = 440; % A4 note frequency in Hz

x = sin(2.*pi.*f.*t); % signal of A4 note

sound(x,fs,16); % plays sound of y at fs samoling rate of 16 bits/sample