A Comparison of Voice Amplifiers and Personal Communication Systems in Individuals With Parkinson's Disease
A Comparison of Voice Amplifiers and Personal Communication Systems in Individuals With Parkinson's Disease
This study will compare two types of assistive devices for communication (a voice amplifier
 and a personal communication system) in individuals with a speech disorder related to
 Parkinson's disease. The performance of these two devices will be examined with measures of
 speech intelligibility and patient questionnaires and rating scales.
The proposed study will involve a comparison of 2 types of communication devices that are
 approved for use in individuals with communication disorders. One of the devices, the voice
 amplifier, is frequently prescribed for individuals with Parkinson's disease and should be
 considered as part of the standard care for the symptom of low speech intensity in this
 disorder. The other device is frequently prescribed for individuals with hearing impairment
 (unrelated to Parkinson's disease) but is not considered to be part of the standard of care
 for individuals with Parkinson's disease. This clinical study will use a crossover design in
 which the participants will receive both devices, one after the other, and the order will be
 randomized across the individuals. There is no control group or placebo.

 This study will include three groups of participants: 1) a PD participant group (n=20), 2) a
 communication partner (CP) group (n=20), and 3) a naïve listener group (n=10). The PD
 participant group will be comprised of individuals who have mild to moderate signs and
 symptoms of idiopathic PD and hypophonia as confirmed by a neurologist. For all individuals
 with PD, the speech testing will occur approximately one hour after taking their
 antiparkinsonian medication according to their regular medication schedule. The communication
 partner group will consist of individuals who regularly converse with the PD participant
 (i.e. spouse or primary caregiver). The naive listener group will consist of students from
 Western University. The participants with PD will wear a head-set microphone (AKG c520). The
 speech intensity of the participants with PD will be calibrated with a sound level meter
 (Luton SL-4001) placed 15cm from the mouth while the participant produces a steady 70dB A
 prolonged "ah" for about 2 seconds. Two additional tripod-mounted microphones (Shure SM48)
 will be placed 2 meters and 4 meters from the PD participant. The communication partner
 participants will be seated approximately 30cm from these two microphones during the 2 and 4
 meter interlocutor distance conditions. The output from the 3 microphones will be connected
 to preamplifiers and a digitizing unit (M-Audio MobilePre) attached via a USB connection to a
 PC computer running Praat recording and analysis software (Boersma & Weenink, 2013). An
 additional, fourth input line will be attached to the digitizing unit from the output of the
 personal communication system when this device is being used in the study. All four audio
 signals will be digitized at 44.1 kHz and 16 bits and stored as uncompressed .wav audio
 files. The voice amplifier and personal communication system will be evaluated in random
 order across the participants. The voice amplifier will be a ChatterVox. This amplifier
 includes a headset microphone wired to a speaker/amplifier unit that is worn on a waist belt.
 The ChatterVox was selected because it is a typical type of voice amplifier that is
 frequently recommended and prescribed to individuals with PD in Ontario. Despite the paucity
 of published voice amplifier studies of PD, the ChatterVox has been used in several published
 studies of non-neurological voice disorders such as studies of elementary school teachers
 with occupational-related voice problems (McCormick & Roy, 2002; Roy et al. 2003). In
 addition, a recent MSc thesis conducted at Western University by Monika Andreetta (supervised
 by Professor Scott Adams) found that the ChatterVox was one of the best performing and
 preferred devices in participants with PD when it was compared to 6 other voice amplifiers.
 The personal communication system that will be evaluated is the Easy Listener FM system
 (Phonic Ear Corp.). This system includes a light-weight, pocket-sized (2.5 x 9.4 x 5.6 cm; 80
 grams) transmitter unit with a head-set microphone and a nearly identical, pocket-sized
 receiver unit with a set of small headphones. These units can be carried in a breast-pocket
 or attached to a waist-belt with a clip. The transmitter and receiver units are wireless and
 communicate via an FM signal. The communication range of the units is approximately 30
 meters. The PD participant will wear the transmitter/microphone unit and the communication
 partner (CP) participant will wear the receiver/headphone unit. While there are several
 personal communication systems that are available, the Easy Listener personal communication
 system has been frequently prescribed and has been used in several previous studies of
 individuals with hearing impairment (Schafer & Thibodeau, 2004). During some of the
 experimental conditions the PD and CP participants will be presented with 65dB A of
 multi-talker noise (using a standard Audiotec Corp. Recording of 4-talker noise). The noise
 will be presented from a computer via an audio amplifier and loudspeaker placed at 2 meters
 from the participants. A sound level meter will be used to calibrate the noise level from the
 loudspeaker. Procedures: Speech Tasks: Once one of the two devices has been attached to the
 participant(s), the PD participant will be given a list of 6 sentences that were randomly
 generated from the Sentence Intelligibility Test software. The PD participant will read aloud
 each sentence and then pause while the communication partner (CP) participant attempts to
 repeat aloud the sentence. The SIT provides intelligibility measures, which are commonly used
 to document effectiveness in intervention programs or outcome studies (Beukelman et al.,
 2007). Furthermore, most of the supportive research for the SIT was completed with dysarthric
 speakers (Beukelman et al., 2007). After the list of 6 sentences are completed the PD
 participant will be given several pictures of people engaged in various activities (i.e.
 fishing, playing baseball, doing dishes, etc.) and the PD participant will make statements
 that describe the pictures while the CP participant repeats aloud each of these statements.
 This will continue until 6 statements (minimum of 5 words each) have been produced/repeated.
 Speech Conditions: The speech tasks will be repeated with no device and while using each of
 the two devices (ChatterVox voice amplifier and Easy Listener personal communication system)
 in two noise conditions (none and 65dB multi-talker noise) and two interlocutor distances (2
 and 4 meters). These conditions will be randomized. Rating Scale Procedures: Immediately
 following the speech tasks the PD and CP participants will be asked to rate their experience
 with the devices using visual analogue scales related to the following five parameters: 1.
 Physical comfort: uncomfortable versus comfortable 2. Visual presentation: unacceptable
 versus acceptable 3. Sound quality: poor sound quality versus good sound quality 4.
 Amplification power: poor amplification versus good amplification 5. Overall preference: low
 preference versus high preference The PD and CP participants will use the five visual
 analogue scales to provide separate ratings for each of the two devices. Following the
 completion of the rating scales the participants will be encouraged to provide additional
 feedback about their impressions of the 2 devices. One Week Trial Periods: After the
 completion of the lab-based speech and rating scale procedures the PD and CP participants
 will be given instructions on the care and use of one of the two devices (i.e. recharging,
 cleaning, volume adjustments, attachment, positioning, etc.) and then take the device home
 for a one week trial period. The participants will be asked to use the device as often as
 they desire but to use the device at least 3 times for a periods of at least one hour over
 the course of the week. The participants will be given a Device Use Diary to write down the
 dates, times, volume settings and contexts that they used the devices. The participants will
 return after one week and complete questionnaires and rating scales related to their
 experience and evaluation of the device. These will include the following: 1. Visual analogue
 scales related to physical comfort, visual presentation, sound quality, amplification power,
 and overall preference. 2. Speech Amplification Satisfaction Scale 3. Quebec User Evaluation
 of Satisfaction with Assistive Technology Scale 4. Psychosocial Impact of Assistive Devices
 Scale (PIADS). Following the completion of these questionnaires and ratings scales, the
 participants will be given instructions on the use and care of the second device and then
 take the device home for another one week trial period. The participants will be asked to use
 the device as often as they desire but to use the device at least 3 times for a periods of at
 least one hour over the course of the week. The participants will be given a Device Use Diary
 to write down the dates, times, volume settings and contexts that they used the devices. The
 participants will return after one week and again complete the previously described
 questionnaires and rating scales related to their experience and evaluation of the device.

 Listening Tasks: Listener participants will listen to pre-recorded speech samples obtained
 from the tripod-mounted microphones. Speech samples will be played in a randomized order.
 Listeners will not be present at the time speech samples are recorded, and they will be
 blinded to all information about the speakers and to the contents of the sentences from both
 the SIT and picture description tasks prior to hearing them. Listeners will be seated at a
 comfortable distance from a loudspeaker, which will be fixed at a comfortable predetermined
 volume, and they will be asked to transcribe the data orthographically on prepared forms that
 will be numbered to match the presentation order of the stimuli. The SIT software will
 compute an intelligibility score by comparing transcribed words and sentences to the stimuli
 on the master lists. For the picture description task, sentences will be transcribed
 independently by the assessor and then compared to the listeners' transcriptions to determine
 the intelligibility score.
Inclusion Criteria:

 -  Diagnosed with Parkinson's disease by a neurologist at least 6 months prior to testing
 • Exhibit mild to moderate signs and symptoms of Parkinson's disease and hypophonia
 (reduced speech intensity) • Stabilized on antiparkinsonian medication

 Exclusion Criteria:

 -  Exhibit severe signs and symptoms of Parkinson's disease • History of stroke or an
 additional neurological or motor control disorder • History of speech impairment that
 is unrelated to Parkinson's disease