Background: SPEAK OUT! has been shown to enhance various aspects of voice such as intensity, prosody, voice quality and perception of voice. However, their impacts on expiration and communication effectiveness have not yet been evaluated. This study aimed to evaluate the effectiveness of the Hybrid SPEAK OUT! method on aerodynamic measurements and patient-reported outcome measures (PROMs) in individuals with Parkinson's disease (PD). Methods: This study included 157 participants with PD who underwent an intensive 8-week multidisciplinary treatment program. The Hybrid SPEAK OUT! method consisted of three sessions per week, including two group sessions and one individual treatment session. Voice-related aerodynamic measures included maximum phonation time (MPT), vocal cord function using the S/Z ratio, and expiratory flow measures including peak expiratory flow (PEF) and peak cough flow (PCF). Two PROMs were included: the Hebrew version of the voice handicap index-10 and communication effectiveness questionnaire. Results: The results of 111 participants were analysed. MPT duration increased, PEF and PCF increased, and better scores were found in PROMs. Conclusion: These findings would appear to support the effectiveness of the Hybrid SPEAK OUT! methods improving function, activity and participation in individuals with PD. However, further research is needed.