8. The speech recognition method according to claim 7 , wherein the step of generating said adapted acoustic model data comprises steps of: calculating by an adding portion a sum of the acoustic model data for the second frame and an intra-frame transfer characteristic value for the second frame; and reading said sum to transform cepstrum acoustic model data into linear spectrum acoustic model data.
8. The speech recognition method according to claim 7 , wherein the step of generating said adapted acoustic model data comprises steps of: calculating by an adding portion a sum of the acoustic model data for the second frame and an intra-frame transfer characteristic value for the second frame; and reading said sum to transform cepstrum acoustic model data into linear spectrum acoustic model data. 9. The speech recognition method according to claim 8 , further comprising: causing the adding portion to read and add said linear spectrum acoustic model data and said echo speech model data to generate the at least one echo prediction coefficient giving the maximum likelihood.