An Acoustic Investigation of the Production of Interdental Fricatives by Cameroonian ESL Learners

This study investigates the production of /θ/ and /ð/ at initial, medial and final positions by Cameroonian ESL (CamESL) students using the acoustic analysis method. The words theme, something, mouth, them, without and with were put on a list and read by 26 undergraduate CamESL learners from the University of Maroua. Their productions were recorded and analysed using PRAAT version 6.3.11 of 17 July 2023. The analysis revealed that at initial and medial positions, the majority of learners were able to accurately render the sounds while at the final position, both /θ/ and /ð/ were systematically substituted with /f/ and the unreleased stops /t ̚/ and /d ̚ /. It was also discovered that the choice of substituting phonemes depends on the linguistic environment sounds since unreleased stops never occurred at initial and medial word positions, and the normal stops /t/ and /d/ also rarely occurred at the final position. It can be concluded that success and deviation in the production of interdental fricatives by CamESL learners depend on the location of the sound.