title: Motor-Learning-Based Adjustment of Ambulatory Feedback on Vocal Loudness for Patients With Parkinson's Disease.
abstract: OBJECTIVE
  To investigate how the direct biofeedback on vocal loudness administered with a portable voice accumulator (VoxLog) should be configured, to facilitate an optimal learning outcome for individuals with Parkinson's disease (PD), on the basis of principles of motor learning.
  
  
  METHODS
  Methodologic development in an experimental study.
  
  
  METHODS
  The portable voice accumulator VoxLog was worn by 20 participants with PD during habitual speech during semistructured conversations. Six different biofeedback configurations were used, in random order, to study which configuration resulted in a feedback frequency closest to 20% as recommended on the basis of previous studies.
  
  
  RESULTS
  Activation of feedback when the wearer speaks below a threshold level of 3 dB below the speaker's mean voice sound level in habitual speech combined with an activation time of 500 ms resulted in a mean feedback frequency of 21.2%.
  
  
  CONCLUSIONS
  Settings regarding threshold and activation time based on the results from this study are recommended to achieve an optimal learning outcome when administering biofeedback on vocal loudness for individuals with PD using portable voice accumulators.
authors.affiliation: Division of Speech and Language Pathology, Department of Clinical Sciences, Intervention and Technology, Karolinska Institutet, Stockholm, Sweden; Department of Speech and Language Pathology, Karolinska University Hospital, Stockholm, Sweden. Electronic address: joakim.gustafsson@ki.se.
authors.forename: Joakim
authors.initials: J
authors.lastname: Gustafsson
authors.affiliation: Department of Speech, Music and Hearing, School of Computer Science and Communication, KTH Royal Institute of Technology, Stockholm, Sweden.
authors.forename: Sten
authors.initials: S
authors.lastname: Ternström
authors.affiliation: Division of Speech and Language Pathology, Department of Clinical Sciences, Intervention and Technology, Karolinska Institutet, Stockholm, Sweden; Department of Speech and Language Pathology, Karolinska University Hospital, Stockholm, Sweden.
authors.forename: Maria
authors.initials: M
authors.lastname: Södersten
authors.affiliation: Division of Speech and Language Pathology, Department of Clinical Sciences, Intervention and Technology, Karolinska Institutet, Stockholm, Sweden; Department of Speech and Language Pathology, Karolinska University Hospital, Stockholm, Sweden.
authors.forename: Ellika
authors.initials: E
authors.lastname: Schalling
mesh_terms: D061725:Accelerometry / Q000295:instrumentation; D000368:Aged; D001676:Biofeedback, Psychology / Q000295:instrumentation / Q000379:methods*; D004867:Equipment Design; D005260:Female; D006801:Humans; D007858:Learning; D008144:Loudness Perception; D008297:Male; D008875:Middle Aged; D009043:Motor Activity; D010300:Parkinson Disease / Q000175:diagnosis / Q000503:physiopathology / Q000523:psychology / Q000628:therapy*; D010699:Phonation; D013061:Speech Acoustics; D013067:Speech Perception; D013068:Speech Production Measurement / Q000295:instrumentation / Q000379:methods*; D013997:Time Factors; D014159:Transducers; D014827:Vocal Cords / Q000503:physiopathology*; D014833:Voice Quality
keywords: Biofeedback; Motor learning; Parkinson's disease; Portable voice accumulators; Voice sound level