I have several voice recordings that I am encoding to mp3 to stream at 16kbps. I was given a sample wav file which encodes to 16kbps mp3 fine and which encodes with a lot of sound artifacts. (wav files below)
I believe I understand why the second file encodes to mp3 with artifacts, because of the high frequency, but what I do not understand is why the second file has such a high frequency. I believe the human voice has a frequency of 300hz to 3400hz (http://en.wikipedia.org/wiki/Voice_frequency) so how is it possible that it has a frequency over 10k?
Also, if the frequency is why the encoding is introducing artifacts, is there a way to record audio such that it is within a certain frequency?