Using Portable Voice Accumulators to Study Transfer of Speech Outcomes Following Intervention - A Feasibility Study.

Objectives: To evaluate the process and scientific feasibility of using a portable voice accumulator (PVA) to study carry-over of treatment effects on speech and voice in people with mild-moderate Parkinson's disease.

Methods: The study was guided by the checklist in Consolidated Standards of Reporting Trials (CONSORT) 2010 statement: extension to randomized pilot and feasibility trials. Participants with Parkinson's disease were recruited within the context of a randomized controlled trial with random allocation to intervention with either HiCommunication, a program targeting speech and communication, or HiBalance, a program targeting balance and strength. Before and after intervention data was collected from standardized studio recordings of speech and registrations of voice use in daily life with the PVA VoxLog.

Results: Fifteen participants were included in the study and sufficient data was yielded from six of them. Reasons for insufficient data included technical issues and difficulties handling the PVA. Changes in voice sound level from pre to post intervention differed at an individual level when assessed in daily life compared to studio recordings. Registrations in daily life provided information on phonation ratio and ability to adapt voice sound level to environmental noise.

Conclusion: This study highlights the challenges of studying intervention effects on voice use in daily life using a PVA. Improvements of test protocols in future studies are suggested. We exemplify how PVA data may generate a more detailed and ecologically valid picture of voice use complementing studio recordings of speech. Finally, we encourage technical development of more user-friendly PVAs.