Python phoneme alignment representation

Phoneme alignment representation for speech tasks. This repo does not perform forced phoneme alignment, but provides an interface for working with the resulting alignment of a forced aligner such as pyfoal.

Installation

pip install pypar

Usage

Creating an alignment

If you already have the alignment saved to a json, mlf, or TextGrid file, pass the name of the file.

alignment = pypar.Alignment(file)

Alignments can be created manually from Word and Phoneme objects. Start and end times are given in seconds.

# Create a word from phonemes
word = pypar.Word(
    'THE',
    [pypar.Phoneme('DH', 0., .03), pypar.Phoneme('AH0', .03, .06)])

# Create a silence
silence = pypar.Word(pypar.SILENCE, pypar.Phoneme(pypar.SILENCE, .06, .16))

# Make an alignment
alignment = pypar.Alignment([word, silence])

You can create a new alignment from existing alignments via slicing and concatenation.

# Slice
first_two_words = alignment[:2]

# Concatenate
alignment_with_repeat = first_two_words + alignment

Accessing words and phonemes

To retrieve a list of words in the alignment, use alignment.words(). To retrieve a list of phonemes, use alignment.phonemes(). The Alignment, Word, and Phoneme objects all define .start(), .end(), and .duration() methods, which return the start time, end time, and duration, respectively. All times are given in units of seconds. These objects also define equality checks via ==, casting to string with str(), and iteration as follows.

# Iterate over words
for word in alignment:

    # Iterate over phonemes in word
    for phoneme in word:

        # Do something with phoneme
        pass

To access a word or phoneme at a specific time, pass the time in seconds to alignment.word_at_time or alignment.phoneme_at_time.

To retrieve the frame indices of the start and end of a word or phoneme, pass the audio sampling rate and hopsize (in samples) to alignment.word_bounds or alignment.phoneme_bounds.

Saving an alignment

To save an alignment to disk, use alignment.save(file), where file is the desired filename. pypar currently supports saving as a json or TextGrid file.

Tests

Tests can be run as follows.

pip install pytest
pytest