Abstract for robinson_tr82

Cambridge University Engineering Department Technical Report CUED/F-INFENG/TR82


Tony Robinson

September 1991

Recurrent Error Propagation Networks have been shown to give good performance on the speaker independent phone recognition task in comparison with other methods (Robinson and Fallside, 1991). This short report describes several recent improvements made to the existing recogniser for the TIMIT database.

The improvements are: an addition to the preprocessor to represent voicing information; use of histogram normalisation on the input channels of the network; normalisation of the output channels to enforce unity sum; a change in the cost function to give equal weighting to each target symbol; a change in the representation of the outputs to reduce quantisation errors; retraining on the complete TIMIT training set; and the better estimation of HMM phone models.

Most of these changes decrease the number of arbitrary parameters used and allow for the integration of the system with standard HMM techniques. The result of these changes is a decrease in the number of errors by about 16% (from 36.5% to 30.7% when all 61 TIMIT phones are used and from 30.2% to 25.0% on a reduced 39 phone set).

(ftp:) robinson_tr82.ps.Z (http:) robinson_tr82.ps.Z
PDF (automatically generated from original PostScript document - may be badly aliased on screen):
  (ftp:) robinson_tr82.pdf | (http:) robinson_tr82.pdf

If you have difficulty viewing files that end '.gz', which are gzip compressed, then you may be able to find tools to uncompress them at the gzip web site.

If you have difficulty viewing files that are in PostScript, (ending '.ps' or '.ps.gz'), then you may be able to find tools to view them at the gsview web site.

We have attempted to provide automatically generated PDF copies of documents for which only PostScript versions have previously been available. These are clearly marked in the database - due to the nature of the automatic conversion process, they are likely to be badly aliased when viewed at default resolution on screen by acroread.