1)Starting from a pure wave of a given frequency (4000 Hz) I can not implement this pseudo code to play a sound (pure wave) whose frequency decreases continuously from 4000 to 200:
t = (0:0.001:100)';
for n = 4000:-1:200
y = sin(2*pi*n*t)
How to implement this correctly?
2)same question but starting from an very short audio file or an sound sample