Acoustic evaluation of voice signal distortion by videoconferencing platforms and devices used in telepractice for cleft palate

The usefulness and effectiveness of telepractice have been reported in recent years. Treatment of cleft palate patients with compensatory articulation is based on perceptual identification. Telepractice using videoconferencing platforms causes voice signal distortion and impacts auditory-perceptual perception. This study aimed acoustically examine voice signal distortion and determine the optimal videoconferencing platforms, in addition to the phonemes that can be discriminated with the same quality as in face-to-face interactions. ATR503 with 50 phoneme-balanced Japanese speech sentences was used as a reference corpus. Four videoconferencing platforms, -Zoom, Cisco Webex, Skype, and Google Meet, -and five devices, -iPhone, Android, iPad Air, Windows, and MacBook Pro were used as transmission conditions to examine voice signal distortions with the objective measure log-spectral distortion (LSD). Tukey's test was conducted to evaluate the degree of consonant distortion related to voicings (voiceless and voiced), places of articulation (bilabial, alveolar, alveolo-palatal, palatal, velar, labial-velar, and glottal), and manners of articulation (plosive, fricative, affricate, tap or flap, nasal, and approximant). With statistically significant differences, voiced, bilabial, labial-velar, nasal, and plosive consonants exhibited smaller distortions. In contrast, voiceless, alveolo-palatal, fricative, and affricate consonants exhibited larger distortions. Google Meet exhibited the lowest distortion among videoconferencing platforms and MacBook exhibited the lowest distortion among devices. This study provides significant insights into the telepractice strategies with the appropriate videoconferencing platform and device, and useful settings for cleft palate patients with compensatory articulations with respect to acoustics.