Mondegreen: A Post-Processing Solution to Speech Recognition Error Correction for Voice Search Queries
This addresses user dissatisfaction from irrelevant search results due to ASR errors, particularly for voice queries in large-scale systems, though it is incremental as it complements existing ASR systems.
The paper tackles the problem of speech recognition errors in voice search queries by introducing Mondegreen, a post-processing text correction method that does not rely on audio signals, and reports significant improvements in user interaction when deployed in Google's search system.
As more and more online search queries come from voice, automatic speech recognition becomes a key component to deliver relevant search results. Errors introduced by automatic speech recognition (ASR) lead to irrelevant search results returned to the user, thus causing user dissatisfaction. In this paper, we introduce an approach, Mondegreen, to correct voice queries in text space without depending on audio signals, which may not always be available due to system constraints or privacy or bandwidth (for example, some ASR systems run on-device) considerations. We focus on voice queries transcribed via several proprietary commercial ASR systems. These queries come from users making internet, or online service search queries. We first present an analysis showing how different the language distribution coming from user voice queries is from that in traditional text corpora used to train off-the-shelf ASR systems. We then demonstrate that Mondegreen can achieve significant improvements in increased user interaction by correcting user voice queries in one of the largest search systems in Google. Finally, we see Mondegreen as complementing existing highly-optimized production ASR systems, which may not be frequently retrained and thus lag behind due to vocabulary drifts.