Assessment of language impact to speech privacy in closed offices

Abstract

Speech privacy is the opposite concept of speech intelligibility and can be assessed by the predictors of speech intelligibility. Based on the existing standards and the research to date, most objective assessments for speech privacy and speech intelligibility, such as articulation index (AI) or speech intelligibility index (SII), speech transmission index (STI), and sound early-to-late ratio (C50), are evaluated by the subjective measurements. However, these subject measurements are based on the studies of English or the other Western languages. The language impact to speech privacy has been overseen. It is therefore necessary to study the impact of different languages and accents in multiculturalism environments to speech privacy. In this study, subjective measurements were conducted in closed office environments by using English and a tonal language, Mandarin. Detailed investigations on the language impact to speech privacy were carried out with the two languages. The results of this study reveal the significant evaluation variations in speech privacy when different languages are used. The subjective measurement results obtained in this study were also compared with the objective measurement employing articulation indices.