Evaluating iPhone Recordings for Acoustic Voice Assessment

Aims: This study examined the viability of using iPhone recordings for acoustic measurements of voice quality. Methods: Acoustic measures were compared between voice signals simultaneously recorded from 11 normal speakers (6 females and 5 males) through an iPhone (model A1303, Apple, USA) and a comparison recording system. Comparisons were also conducted between the pre- and post-operative voices recorded from 10 voice patients (4 females and 6 males) through the iPhone. Participants aged between 27 and 79 years. Results: Measures from iPhone and comparison signals were found to be highly correlated. Findings of the effects of vowel type on the selected measures were consistent between the two recording systems and congruent with previous findings. Analysis of the patient data revealed that a selection of acoustic measures, such as vowel space area and voice perturbation measures, consistently demonstrated a positive change following phonosurgery. Conclusion: The present findings indicated that the iPhone device tested was useful for tracking voice changes for clinical management. Preliminary findings regarding factors such as gender and type of pathology suggest that intra-subject, instead of norm-referenced, comparisons of acoustic measures would be more useful in monitoring the progression of a voice disorder or tracking the treatment effect.