A miniature accelerometer and microphone can be used to obtain Horii Oral-Nasal Coupling (HONC) scores to objectively measure nasalization of speech. While this instrumentation compares favorably in terms of size and cost relative to other objective measures of nasality, the metric has not been well characterized in children. Furthermore, the measure is known to be affected by vowel loading, as speech loaded with "high" vowels is consistently scored as more nasal than speech loaded with "low" vowels. Filtering the signals used in computation of the HONC score to better isolate the correlates of nasalization has been shown to reduce vowel-related effects on the metric, but the efficacy of filtering has thus far only been explored in adults. Here, HONC scores for running speech and the vowel portions of consonant-vowel-consonant tokens were calculated for the speech of 26 children, aged 4-9 yrs. Scores were computed using the broadband accelerometer and speech signals, as well as using filtered, low-frequency versions of these signals. HONC scores obtained using both broadband and filtered signals resulted in well-separated scores for nasal and non-nasal speech. HONC scores computed using filtered signals were found to exhibit less withinparticipant variability.

Purpose: The purpose of this study was to determine the effects of biofeedback on control of nasalization in individuals with typical speech. Method: Forty-eight individuals with typical speech attempted to increase and decrease vowel nasalization. During training, stimuli consisted of consonant-vowelconsonant (CVC) tokens with the center vowels /a/ or /i/ in either a nasal or nonnasal phonemic context (e.g., /mim/ vs. /bib/), depending on the participant's training group. Half of the participants had access to augmentative visual feedback during training, which was based on a less-invasive acoustic, accelerometric measure of vowel nasalizationthe Horii oral-nasal coupling (HONC) score. During pre-and posttraining assessments, acoustically based nasalance was also measured from the center vowels /a/, /i/, /ae/, and /u/ of CVCs in both nasal and nonnasal contexts. Results: Linear regressions indicated that both phonemic contexts (nasal or nonnasal) and the presence of augmentative visual feedback during training were significant predictors for changes in nasalance scores from pre-to posttraining. Conclusions: Participants were able to change the nasalization of their speech following a training period with HONC biofeedback. Future work is necessary to examine the effect of such training in individuals with velopharyngeal dysfunction.

Instrumentation-based scoring methods can be used to supplement auditory assessments, providing a more objective assessment of voice quality. One such metric that can be used to assess resonance disorders, the Horii Oral Nasal Coupling Index (HONC), has been shown to successfully separate nasal from nonnasal utterances, but has not been extensively studied in children. We have previously found that using low-pass filtered versions of the nasal accelerometer and microphone signal used in its computation can reduce variability due to vowel placement that is traditionally reported for these scores, and sought to determine whether this reduction in variability would extend to children's speech. We obtained nasal acceleration and speech signals from 26 children, aged 4–9, during the production of various consonant-vowel-consonant tokens and running speech with controlled vowel and consonant loading. HONC scores were compared using broadband and low-frequency portions of these signals. It was found that applying a low-frequency filter reduced the variability of the HONC scores due to vowel type relative to when broadband signals were used, and the scores could discriminate vowels produced in nasal and non-nasal contexts in children with high accuracy. These results demonstrate the potential of HONC scores as an aid in rehabilitating hypernasal speech.