Does Portable Voice Amplification Improve Vocal Outcomes in Elementary School Teachers? Evidence From Aerodynamic, Acoustic, and Self-Reported Measures

PURPOSE: The present study aimed at evaluating the impact of a voice amplification system plus vocal hygiene on aerodynamic, acoustic, and self-reported outcomes in elementary school teachers with and without voice problems. METHOD: A total of 217 elementary school teachers were initially recruited: 108 normal-voiced participants and 109 participants with voice complaints. Participants from both groups were assessed before and after voice intervention, with aerodynamic, acoustic, and self-reported outcomes being observed. Participants were randomly assigned to one of two treatments before starting voice intervention procedures: (a) use of amplification system in their classroom setting plus vocal hygiene program (experimental condition) and (b) vocal hygiene program only (control condition). Thus, four groups were generated for this study. Data were analyzed by implementing mixed-effects models for all dependent variables. RESULTS: For dysphonic teachers, significant interactions were observed on Vocal Fatigue Index, Voice Handicap Index, and Vocal Tract Discomfort Scale values, reflecting greater improvement for the experimental group as compared to the control group once the intervention was completed. In contrast, no differential effects were observed for smoothed cepstral peak prominence, airflow rate, subglottal pressure, or phonation threshold pressure. Only one significant interaction was detected in participants with normal voices, suggesting that treatment is more effective for teachers already suffering from dysphonia. CONCLUSIONS: Portable amplification system plus vocal hygiene seems to positively impact dysphonic school teachers' voice, especially in terms of self-reported improvements in functional, physical, and emotional voice-related dimensions; throat discomfort; and vocal fatigue symptoms. No statistically significant changes were observed for aerodynamic or acoustic outcomes. These findings, along with prior evidence, suggest that voice amplification may be most beneficial when implemented as one component of a broader approach to occupational vocal health, combined with other strategies such as voice training and classroom acoustic interventions.