Automatic Speech Recognition (ASR) Evaluation
This is a simple utility to perform a quick evaluation on the results generated by any Speech to text (STT) or Automatic Speech Recognition (ASR) System.
This utility can calculate following metrics -
- Word Error Rate (WER), which is a most common metric of measuring the performance of a Speech Recognition or Machine translation system
- Levenshtein Distance calculated at word level.
- Number of Word level insertions, deletions and mismatches between the original file and the generated file.
- Number of Phrase level insertions, deletions and mismatches between the original file and the generated file.
- Color Highlighted text Comparison to visualize the differences.
- General Statistics about the original and generated files (bytes, characters, words, new lines etc.)
The utility also performs the pre-processing or normalization of the text in the provided files based on following operations -
- Remove Speaker Name: Remove Speaker name at the beginning of the line.
- Remove Annotations: Remove any custom annotations added during transcriptions.
- Remove Whitespaces: Remove any extra white spaces.
- Remove Quotes: Remove any double quotes
- Remove Dashes: Remove any dashes
- Remove Punctuations: Remove any punctuations (.,?!)
- Convert contents to lower case
Make sure that you have NodeJS v8+ installed on your system.
npm install -g asr-eval
Verify installation by simply running:
Simplest way to run your first evaluation is by simply passing
generated options to
original is a plain text file containing original transcript to be used as reference; usually this is generated by human beings.
generated is a plain text file containing generated transcript by the STT/ASR system.
asr-eval --original ./original-file.txt --generated ./generated-file.txt
This would print simply the Word Error Rate (WER) between the provided files. This is how the output should look like:
Word Error Rate (WER): 13.61350109561817%
To find more information about all the available options:
All the available usage options would be printed:
Synopsis $ asr-eval --original file --generated file $ asr-eval [options] --original file --generated file $ asr-eval --help Options -o, --original file Original File to be used as reference. Usually, this should be the transcribed file by a Human being. -g, --generated file File with the output generated by Speech Recognition System. -e, --wer Default: true. Print Word Error Rate (WER). --distance Default: false. Print total word distance after comparison. -e, --stats Default: false. Print statistics about original and generate files, before and after pre-processing. Also prints statistics about word level and phrase level differences. --pairs Default: false. Print all the difference pairs with type of difference. -c, --textcomparison Default: false. Print the text comparison between two files with highlighting. -s, --removespeakers Default: true. Remove the speaker at the start of each line in files before calculations. The speaker should be separated by colon ":" i.e. speaker_name: text For e.g. "John Doe: Hello, I am John." would get converted to simply "Hello, I am John." -a, --removeannotations Default: true. Remove any custom annotations in the transcript before calculations. This is useful when removing custom annotations done by human transcribers. Anything in square brackets  are detected as annotations. For e.g. "Hello, I am [inaudible 00:12] because of few reasons." would get converted to "Hello, I am because of few reasons." -w, --removewhitespaces Default: true. Remove any extra white spaces before calculations. -q, --removequotes Default: true. Remove any double quotes '"' from the files before calculations. -d, --removedashes Default: true. Remove any dashes (hyphens) "-" from the files before calculations. -p, --removepunctuations Default: true. Remove any punctuations ".,?!" from the files before calculations. -l, --lowercase Default: true. Convert both files to lower case before calculations. This is useful if evaluation needs to be done in case-insensitive way. -h, --help Print this usage guide.