×

Speech recognition apparatus and method and program therefor

  • US 8,510,111 B2
  • Filed: 02/08/2008
  • Issued: 08/13/2013
  • Est. Priority Date: 03/28/2007
  • Status: Active Grant
First Claim
Patent Images

1. A speech recognition apparatus comprising:

  • a generating unit configured to generate a speech feature vector expressing a speech feature for each of a plurality of frames obtained by dividing an input speech between a start time and an end time and including frames from a start frame to an end frame;

    a first storage unit configured to store a first acoustic model obtained by modeling a speech feature of each word by using a state transition model including a plurality of states and a plurality of transition paths, each word being included in the input speech;

    a second storage unit configured to store at least one second acoustic model different from the first acoustic model;

    a first calculation unit configured to calculate, for each state, a first probability of transition to a state at the end frame for each word from the first acoustic model and a speech feature vector sequence from the start frame to the end frame to obtain a plurality of first probabilities for each word, and select a maximum probability of the first probabilities;

    a selection unit configured to select, for each word, a maximum probability transition path corresponding to the maximum probability, the maximum probability transition path indicating transition from a start state at the start frame to an end state at the end frame;

    a conversion unit configured to convert, for each word, the maximum probability transition path into a corresponding transition path corresponding to the second acoustic model;

    a second calculation unit configured to calculate, for each word, a second probability of transition to the state at the end frame on the corresponding transition path from the second acoustic model and the speech feature vector sequence; and

    a finding unit configured to find, as a recognized word, a word corresponding to a maximum value among the maximum probability for each word at the end frame and the second probability for each word at the end frame.

View all claims
  • 4 Assignments
Timeline View
Assignment View
    ×
    ×