Influence of Altered Auditory Feedback on Oral-Nasal Balance in Song

Interlocutor accommodation of gradually altered nasal signal levels in a model speaker

BACKGROUND

Phonetic accommodation is observed when interacting speakers gradually converge (or diverge) on phonetic features over the course of a conversation. The present experiment investigated whether gradual changes in the nasal signal levels of a pre-recorded model speaker would lead to accommodation in the nasalance scores of the interlocutor in a speech-shadowing experiment.

METHODS

Twenty female speakers in two groups repeated sentences after a pre-recorded model speaker whose nasal signal level was gradually increased or decreased over the course of the experiment. Outcome measures were the mean nasalance scores at the initial baseline, maximum nasal signal level, minimum nasal signal level and final baseline conditions. The order of presentation of the maximum and minimum nasal signal levels was varied between the two groups.

RESULTS

The results showed a significant effect of condition in F(3) = 2.86, p = 0.045. Both groups of participants demonstrated lower nasalance scores in response to increased nasal signal levels in the model (phonetic divergence). The group that was first presented with the maximum nasal signal levels demonstrated lower nasalance scores for the minimum nasal signal level condition (phonetic convergence).

CONCLUSION

Speakers showed a consistent divergent reaction to a more nasal-sounding model speaker, but their response to a less nasal-sounding model may depend on the order of presentation of the manipulations. More research is needed to investigate the effects of increased versus decreased nasality in the speech of an interlocutor.

Effectiveness of oral motor respiratory exercise and vocal intonation therapy on respiratory function and vocal quality in patients with spinal cord injury: a randomized controlled trial

Singing, as a method of combining respiratory function exercise and vocal intonation therapy, provides a new direction for respiratory function exercise in patients with spinal cord injury. This randomized controlled trial investigated the effects of oral motor respiratory exercise and vocal intonation therapy on respiratory function and vocal quality in patients with spinal cord injury. Among 31 included patients with spinal cord injury, 18 completed the treatment. These 18 patients were randomly assigned to undergo music therapy (intervention group, 30 min/d, 5 times a week, for a total of 12 weeks; n = 9, 7 males and 2 females; 30.33 ± 11.74 years old) or normal respiratory training (control group, n = 9; 8 males and 1 female; 34.78 ± 11.13 years old). Both patient groups received routine treatment concurrently. Before and at 6 and 12 weeks after intervention, a standard respiratory function test, a voice test, the St. George's Respiratory Questionnaire, and a quality of life questionnaire were administered. The results showed that the inspiratory capacity, forced expiratory volume in 1 second, forced vital capacity, maximal mid-expiratory flow rate, sing-loud pressure level, and sustained note length were significantly increased in the intervention group compared with the control group. The St. George's Respiratory Questionnaire and quality of life results of patients in the intervention group were significantly superior to those in the control group. These findings suggest that oral motor respiratory exercise and vocal intonation therapy, as respiratory training methods in music therapy, are effective and valuable for improving respiratory dysfunction and vocal quality in patients with spinal cord injury. This study was approved by the Ethics Committee of China Rehabilitation Research Center (approval No. 2019-78-1) on May 27, 2019 and was registered with the Chinese Clinical Trial Registry (registration number: ChiCTR1900026922) on October 26, 2019.

Effects of Knowledge of Task on Control of Oral-Nasal Balance in Speech

<b><i>Introduction:</i></b> Previous research has shown that altering the nasal signal level auditory feedback changed the control of oral-nasal balance in normal speakers. The present study investigated whether knowledge of the task and the instruction not to compensate would change the participants’ response to the manipulation. <b><i>Methods:</i></b> Twenty participants (10 females) in 2 groups continuously repeated a sentence while their nasal signal level was increased or decreased and fed back to them via headphones, so the speakers heard themselves as more or less nasal, respectively. After the first recording session, participants were debriefed about the true nature of the experiment. They were instructed not to compensate in the second recording session. The outcome measures were the percentage changes of nasalance scores from the first baseline. <b><i>Results:</i></b> Statistical analysis using a repeated measures analysis of variance showed an effect of the nasal signal level, <i>F</i>(5,80) = 2.51, <i>p</i> = 0.049, and a nasal signal level by knowledge of task interaction effect, <i>F</i>(5,80) = 3.25, <i>p</i> = 0.019. Post hoc tests showed that the maximum nasal signal level auditory feedback resulted in a significant decrease of nasality from the initial baseline. <b><i>Conclusion:</i></b> Despite knowledge of the task, speakers were unable to resist compensating. As found in previous research, there was a numerically higher compensation response at the maximum than at the minimum nasal signal level auditory feedback condition.