MeetEval: A Toolkit for Computation of Word Error Rates for Meeting Transcription Systems
Thilo von Neumann, Christoph Boeddeker, Marc Delcroix, Reinhold Haeb‐Umbach
Abstract
MeetEval is an open-source toolkit to evaluate all kinds of meeting transcription systems.It provides a unified interface for the computation of commonly used Word Error Rates (WERs), specifically cpWER, ORC WER and MIMO WER along other WER definitions.We extend the cpWER computation by a temporal constraint to ensure that only words are identified as correct when the temporal alignment is plausible.This leads to a better quality of the matching of the hypothesis string to the reference string that more closely resembles the actual transcription quality, and a system is penalized if it provides poor time annotations.Since word-level timing information is often not available, we present a way to approximate exact wordlevel timings from segment-level timings (e.g., a sentence) and show that the approximation leads to a similar WER as a matching with exact word-level annotations.At the same time, the time constraint leads to a speedup of the matching algorithm, which outweighs the additional overhead caused by processing the time stamps.