9. The method of claim 1 , wherein generating the first voice activity indicator value includes normalizing a function of the difference between the first value and the second value.
9. The method of claim 1 , wherein generating the first voice activity indicator value includes normalizing a function of the difference between the first value and the second value. 10. The method of claim 9 , wherein normalizing the difference between the first value and the second value comprises one of: dividing the difference by a function of the sum of the first value and the second value; dividing the difference by a function of an integral value of the spectrum amplitude of the audible signal over a first frequency range that includes the candidate pitch.