14. An apparatus for coding a first signal at a predetermined bit rate, the first signal reflecting speech information and comprising sets of signal segments, each set comprising a plurality of N signal segments, the apparatus comprising: a. a first speech coder for coding the N signal segments of a set to provide a first coded representation for each of the N signal segments; b. means for forming a second signal for each of one or more of the N signal segments, the second signal reflecting speech information not coded by the first speech coder; and c. a second speech coder for coding a number, M, of second signals responsive to coding criterion to provide a second coded representation for each of said M second signals, where 1.ltoreq.M.ltoreq.N-1 and where the number of second signals coded, M, is determined based on the predetermined bit rate; such that, of said N signal segments, a number, P, of said signal segments are coded with use of the first speech coder, said M signal segments are coded with use of both the first and second speech coders, and wherein N=P+M.
15. The apparatus of claim 14 wherein the second signal comprises a residual signal reflecting a difference between a signal segment and said signal segment's quantized representation provided by the first speech coder.