[character] Name of the column with graphemes. Defaults to "GRAPHEME".
col.meta
[character] Name of the column with the coverage of metacharacters. If empty string or NA, the column will be generated automatically. Defaults to "META".
col.value
[character] Name of the column with values of graphemes. Defaults to "VALUE".
Value
[transcription] A transcription object containing the read transcription.