1. A method of signal processing, said method comprising: performing a coding operation on a portion in time of a digitized audio signal, wherein said coding operation includes an ordered plurality of iterations; at each of the ordered plurality of iterations, calculating a value of a measure relating to a gain of the coding operation; for each of a first plurality of threshold values, determining the iteration, among the ordered plurality, at which a change occurs in a state of a first relation between the calculated value and the threshold value, and storing an indication of the iteration; and comparing at least one of the stored indications to at least one corresponding threshold value.