Hey all
I once read about a simple and robust way to perform latency measurements with an audio signal.
Explained in a few words, the test signal consists of a sweeping sine tone. The return signal ring-modulates the source signal and the resulting signal consists of two frequencies, the sum ( f_src+f_ret ) and difference ( f_src - f_ret), while the lower frequency is proportional to the latency and can be detected quite easily with with e.g. [sigmund~].
I have troubles finding the name of this algorithm and don't remember the original source. I would like to read more about it and correctly attribute the original author / inventor.
Thanks, Roman