An examination into the effects of speech rate on perceived stress in monolingual and bilingual populations

Stress is the body’s response to adverse or demanding circumstances and can cause physical changes such as increased respiratory rate and increased vocal cord muscle tension which can affect speech production and the acoustic properties of speech such as speech rate (duration). Acoustic properties such as duration and intensity act as cues in stress judgements, with duration proving to be the factor that provides the greatest fluctuation in these judgements. In the present study, 55 monolingual and bilingual (Spanish and English speaking) participants listened to 6 audio files spoken at 3 varying speeds in both English and Spanish and rated how stressed they perceived the speaker to be. Contrary to what was predicted, the results demonstrated high intra-cultural similarities in terms of perceptions of stress. As hypothesised, higher stress ratings were attributed to the faster spoken files, although they were also attributed to those files spoken in Spanish. There were interactions between the speed of audio and participant group, language spoken and participant group, speed of audio and language spoken and finally speed of audio, language being spoken and participant group. These results demonstrate that speech rate has significant effects on perceptions of stress and also suggest that the effect of speech rate on these perceptions varies between languages However, previous literature would suggest that the acoustic properties of speech are affected differently in real life scenarios compared to when speech is manipulated artificially. Suggesting that further research should endeavour to avoid electronically manipulated audios, instead capturing naturally occurring audio files