The impact of retainers on sound production of the voiceless alveolar fricative

• Main Author: Cheah, Jamie Si Hui
• Other Authors: Scott Reid Moisik
• Format: Final Year Project
• Language: English
• Published: Nanyang Technological University 2023
• Subjects: Humanities::Linguistics
• Online Access: https://hdl.handle.net/10356/165171
• Institution: Nanyang Technological University

The present study was carried out in order to investigate the impact of long-term wearers of vacuum-formed retainers on the sound production of the voiceless alveolar fricative. Ethnically Singaporean Chinese females (N = 15) between 21 to 65 years old that speak English were selected to participate in this study. Participants completed an articulation test and productions of the voiceless alveolar fricative were collected. Acoustic analyses were conducted using Praat to obtain the centre of gravity measurements for each individual voiceless alveolar fricative. Two paired sample t-tests were carried out to determine if there was a significant difference in the production of /s/ sound when vacuum-formed retainers are worn. Results of the study supported the conclusion that even long-term wearers of vacuum-formed retainers still experience a significant drop in the centre of gravity due to the posterior shift of the articulatory positions of the voiceless alveolar fricative. However, it is important to note that interspeaker variation and coarticulation could affect the results of the centre of gravity. Given its limited demographic sampling, further research needs to be done on other demographic segmentation such as ethnicity, gender, and variation of language in order to better understand if the results from this study can be reproduced again and also replicated to the rest of the population.