A method and apparatus for modifying the level of a speech signal is
provided in which the gain parameter in the encoded speech signal is
changed in a variable and cyclical manner over time. More specifically, a
speech signal is encoded as a bit stream and the speech signal is
transported in frames with each frame potentially being further
sub-divided into sub-frames. The gain parameter, e.g., fixed codebook
gain, is modified in the speech signal in a variable and cyclical manner
over a plurality of frames or sub-frames so that gain is temporally
dispersed over a plurality of frames or sub-frames. In effect, the change
in the amount of gain applied to the signal is effectively dispersed over
time so that gradual and accurate changes in the output level of the
signal can be achieved to better match actual signal conditions.