for 4KHz then for noisy channel using Shannon theorem, sampling rate will be 8K samples/sec. So with 2 bit encoding, 2 bits are sent per sample. So the data rates is 8000 samples / sec * 2 bits = 16000bits / sec = 16kbps.
to my knowledge no.
sometimes a nurse may pretend shes/he is taking your pulse while she/he is actually watching how many breaths per Minuit you are taking. they do this because if a nurse would...