Bug in phoneme to word conversion -- duplicate words

[jhkonan]

Something seems to be not right with how SIL is used in the word transcriptions.

This is the first example in the LibriSpeech Test set.

Here is the true transcript:

HE BEGAN A CONFUSED COMPLAINT AGAINST THE WIZARD WHO HAD VANISHED BEHIND THE CURTAIN ON THE LEFT

Here is the forced aligned word transcript:

array([['0.0', '0.23', '[SIL]'],
       ['0.23', '0.33', 'he'],
       ['0.33', '0.65', 'began'],
       ['0.65', '0.69', 'a'],
       ['0.69', '1.21', 'confused'],
       ['1.21', '1.62', 'complaint'],
       ['1.62', '1.93', 'against'],
       ['1.93', '2.01', 'the'],
       ['2.01', '2.41', 'wizard'],
       ['2.41', '2.56', '[SIL]'],
       ['2.56', '2.57', 'wizard'],
       ['2.57', '2.63', '[SIL]'],
       ['2.63', '2.75', 'who'],
       ['2.75', '2.84', 'had'],
       ['2.84', '3.26', 'vanished'],
       ['3.26', '3.59', 'behind'],
       ['3.59', '3.66', 'the'],
       ['3.66', '4.02', 'curtain'],
       ['4.02', '4.15', 'on'],
       ['4.15', '4.23', 'the'],
       ['4.23', '4.66', 'left'],
       ['4.66', '4.89', '[SIL]']], dtype='<U32')

Here is the forced aligned phonetic transcript:

array([['0.0', '0.23', '[SIL]'],
       ['0.23', '0.3', 'HH'],
       ['0.3', '0.33', 'IY'],
       ['0.33', '0.39', 'B'],
       ['0.39', '0.44', 'IH'],
       ['0.44', '0.53', 'G'],
       ['0.53', '0.6', 'AE'],
       ['0.6', '0.65', 'N'],
       ['0.65', '0.69', 'AH'],
       ['0.69', '0.77', 'K'],
       ['0.77', '0.81', 'AH'],
       ['0.81', '0.86', 'N'],
       ['0.86', '0.97', 'F'],
       ['0.97', '1.02', 'Y'],
       ['1.02', '1.1', 'UW'],
       ['1.1', '1.16', 'Z'],
       ['1.16', '1.21', 'D'],
       ['1.21', '1.26', 'K'],
       ['1.26', '1.3', 'AH'],
       ['1.3', '1.34', 'M'],
       ['1.34', '1.44', 'P'],
       ['1.44', '1.49', 'L'],
       ['1.49', '1.55', 'EY'],
       ['1.55', '1.58', 'N'],
       ['1.58', '1.62', 'T'],
       ['1.62', '1.66', 'AH'],
       ['1.66', '1.74', 'G'],
       ['1.74', '1.78', 'EH'],
       ['1.78', '1.84', 'N'],
       ['1.84', '1.9', 'S'],
       ['1.9', '1.93', 'T'],
       ['1.93', '1.96', 'DH'],
       ['1.96', '2.01', 'AH'],
       ['2.01', '2.1', 'W'],
       ['2.1', '2.15', 'IH'],
       ['2.15', '2.26', 'Z'],
       ['2.26', '2.34', 'ER'],
       ['2.34', '2.41', 'D'],
       ['2.41', '2.56', '[SIL]'],
       ['2.56', '2.57', 'D'],
       ['2.57', '2.63', '[SIL]'],
       ['2.63', '2.7', 'HH'],
       ['2.7', '2.75', 'UW'],
       ['2.75', '2.78', 'HH'],
       ['2.78', '2.8', 'AE'],
       ['2.8', '2.84', 'D'],
       ['2.84', '2.95', 'V'],
       ['2.95', '3.04', 'AE'],
       ['3.04', '3.09', 'N'],
       ['3.09', '3.15', 'IH'],
       ['3.15', '3.23', 'SH'],
       ['3.23', '3.26', 'T'],
       ['3.26', '3.3', 'B'],
       ['3.3', '3.35', 'IH'],
       ['3.35', '3.43', 'HH'],
       ['3.43', '3.53', 'AY'],
       ['3.53', '3.56', 'N'],
       ['3.56', '3.59', 'D'],
       ['3.59', '3.62', 'DH'],
       ['3.62', '3.66', 'AH'],
       ['3.66', '3.78', 'K'],
       ['3.78', '3.9', 'ER'],
       ['3.9', '3.93', 'T'],
       ['3.93', '3.96', 'AH'],
       ['3.96', '4.02', 'N'],
       ['4.02', '4.09', 'AA'],
       ['4.09', '4.15', 'N'],
       ['4.15', '4.19', 'DH'],
       ['4.19', '4.23', 'AH'],
       ['4.23', '4.36', 'L'],
       ['4.36', '4.47', 'EH'],
       ['4.47', '4.58', 'F'],
       ['4.58', '4.66', 'T'],
       ['4.66', '4.89', '[SIL]']], dtype='<U32')

I suspect this may indicate a general problem with the phoneme to word conversion.

[lingjzhu]

Hi,

Thank you! This is indeed a bug in phoneme-to-word conversion. The model performs silence detection and alignment at the same time. The phones and words were first aligned to non-silent audio frames and then merged with the silent frames. This error occurred when silence was detected within a word and it caused a problem when merging non-silent and silent frames. This is indeed a problem and it does not seem to occur very frequently in my earlier tests. I will try to improve it when I have more time. Sorry for the bug.

[teinhonglo]

Any updated?