Acoustic model creating method, acoustic model creating apparatus, acoustic model creating program, and speech recognition apparatus

摘要

Exemplary embodiments of the invention enhance the recognition ability by optimizing the distribution numbers for respective states that constitute an HMM (for example, a syllable HMM). Exemplary embodiments provide a distribution number setting device to increment the distribution number step by step for each state in an HMM; an alignment data creating unit to create alignment data by matching each state having been set to a specific distribution number to training speech data; a description length calculating unit to find, according to the Minimum Description Length criterion, a description length of each state in an HMM having the present time distribution number and a description length of each state in an HMM having the immediately preceding distribution number, with the use of the alignment data; and an optimum distribution number determining device to set an optimum distribution number to each state on the basis of the size of the description length found for each state in the HMM having the present time distribution number and the description length found for each state in the HMM having the immediately preceding distribution number.