A Sociolinguistic Analysis of Automatic Speech Recognition Bias in Newcastle English

TL;DR

This study analyzes how dialectal and social variations in Newcastle English influence ASR errors, revealing that phonological features and social factors significantly affect recognition accuracy, highlighting the need for sociolinguistic considerations in ASR development.

Contribution

It provides a sociolinguistic framework for understanding ASR bias in regional dialects, emphasizing the importance of community-based data and dialect-specific features for improving speech technology.

Findings

Phonological variation explains most recognition errors.

Error rates are higher for men and extreme age groups.

Dialect-specific features like vowel quality cause recurrent failures.

Abstract

Automatic Speech Recognition (ASR) systems are widely used in everyday communication, education, healthcare, and industry, yet their performance remains uneven across speakers, particularly when dialectal variation diverges from the mainstream accents represented in training data. This study investigates ASR bias through a sociolinguistic analysis of Newcastle English, a regional variety of North-East England that has been shown to challenge current speech recognition technologies. Using spontaneous speech from the Diachronic Electronic Corpus of Tyneside English (DECTE), we evaluate the output of a state-of-the-art commercial ASR system and conduct a fine-grained analysis of more than 3,000 transcription errors. Errors are classified by linguistic domain and examined in relation to social variables including gender, age, and socioeconomic status. In addition, an acoustic case study of selected vowel features demonstrates how gradient phonetic variation contributes directly to misrecognition. The results show that phonological variation accounts for the majority of errors, with recurrent failures linked to dialect-specific features like vowel quality and glottalisation, as well as local vocabulary and non-standard grammatical forms. Error rates also vary across social groups, with higher error frequencies observed for men and for speakers at the extremes of the age spectrum. These findings indicate that ASR errors are not random but socially patterned and can be explained from a sociolinguistic perspective. Thus, the study demonstrates the importance of incorporating sociolinguistic expertise into the evaluation and development of speech technologies and argues that more equitable ASR systems require explicit attention to dialectal variation and community-based speech data.