Vocal Acoustics and Aerodynamics During Scripted Reading Compared to Spontaneous Speech

Examination of vocal acoustics and phonatory aerodynamics during connected speech provide a more ecologically valid approach to voice assessment than single phoneme measures. The purpose of the current investigation was to determine if differences exist in vocal acoustics and aerodynamics between reading and spontaneous speech tasks in patients with common voice disorders.

The Emory University Institutional Review Board approved this retrospective study. The voice records of 100 patients (74 females and 26 males) diagnosed with benign voice disorders and referred for voice evaluation at the Emory Voice Center between November 2018 and March 2019 were analyzed. These consisted of reading a scripted passage (the Rainbow Passage) and spontaneous speech (describing how to make a peanut butter and jelly sandwich). Data collected included gender, voice diagnosis, mean fundamental frequency (F₀), mean airflow during voicing, and mean inspiratory airflow (MIA).

Univariate analysis assessed normality of the data. Variables with normal distribution utilized paired t test. Non-normal data were log transformed. Mean F₀ was not significant for complete case analysis (P = 0.053) but gender based stratified analysis, for females (mean difference = 4.68 Hz; 95% CI = 0.359, 9.0012; P = 0.03). Gender-related statistical differences were also found in MIA in women (P = 0.0001), and P = 0.0003 for MIA in men. The direction and range of change between scripted reading and the spontaneous speech tasks in all metrics varied widely. No consistent patterns were noted in gender, age and diagnosis across the parameters studied. However, clinically salient findings in the range of MIA were noted in a small subgroup of participants.

This study suggests that multiple testing stimuli for phonatory aerodynamic and acoustic outcomes measurement may be appropriate for use depending on the need and vocal challenges of the individual patient. Clinically, both structured reading and spontaneous speech provide valuable insight into the vocal capabilities of the patient.