Immediate Effects of Personal Sound Amplification Products on Speech Processing
Phase: NA
Conditions: Hearing Loss, Age-Related
Sponsor: Rotman Research Institute at Baycrest

Study Protocol and Statistical Analysis Plan
1
Effects of PSAPs on Speech Processing 
NCT05076045    
Study Protocol 
March 14, 2022 

Study protocol 
 
2
Background Information 
 
Hearing loss is the third most common chronic disability among Canadian seniors. Mild to 
moderate hearing loss in older adults is associated with communication deficits, including 
difficulty following a conversation in a noisy environment. It is also associated with accelerated 
cognitive decline and the early onset of dementia. In a recent study by our team (Perron et al., 
submitted), we showed that older adults who reported hearing problems had poorer executive 
functions than those who reported few hearing problems, suggesting a strong link between 
cognition and hearing. 
 
Yet, despite its adverse effects on communication skills and cognition, mild to moderate hearing 
loss remains largely untreated, with only 20% of older adults with a hearing loss having access to 
hearing aids. In most Canadian provinces, Health Insurance covers only a portion of the cost of 
hearing aids, which can be thousands of dollars, making them unaffordable for many older adults.  
 
A promising and much cheaper alternative is personal sound amplification products (PSAPs), 
electronic, portable, over-the-counter devices amplifying sound. They are analogues to drugstore 
reading glasses and do not require a prescription or hearing evaluation. PSAPs are becoming 
increasingly popular as millions of people in the United States use these devices to compensate for 
their hearing loss.  
 
However, it remains an open question whether PSAPs can effectively reduce the adverse effects 
of hearing loss. As these devices gain popularity, there is an urgent need to objectively evaluate 
the impact of PSAPs on auditory processing and communication skills. 
 
Research Question and Hypothesis 
 
This research investigates the immediate neurobiological and behavioural effects of PSAP use on 
speech-in-noise performance. The specific objectives are to: 
 
1) Clarify whether using PSAPs is associated with improved speech perception in noise 
compared to an unaided condition in individuals with normal hearing or mild to moderate 
hearing loss. 
2) Determine the role of listener characteristics, such as age, sex, education, self-reported 
hearing loss, objective hearing loss, and cognitive status, on performance during PSAPs 
use. 
3) Study the neurobiological mechanisms of benefit using electroencephalography (EEG). 
 
Our hypotheses are twofold:  
 
1) We expect that wearing PSAPs for a single session will improve performance and lower 
self-reported listening effort during speech-in-noise perception. 
2) We expect that the behavioural benefits of PSAPs will be associated with increased brain 
activity in auditory areas and increased functional connectivity between auditory and 
speech regions. 
 

Study protocol 
 
3
Method 
 
Participants: A total of 32 participants will be recruited. This sample size is similar to or larger 
than other studies examining the impact of PSAPs. Participants will be adults between the ages of 
60 and 90 with normal hearing or mild to moderate hearing loss (no clinical diagnosis) who have 
never used hearing aids or any other type of hearing device. 
 
Participants will be recruited through the Rotman Research Institute participant database. The 
selection of participants from the database will be based primarily on the hearing test results 
already available in the database. If necessary, additional participants will be recruited through 
advertisements. 
 
Participation is voluntary and anonymous. All participants will sign a consent form before the start 
of the study and receive a modest stipend of $15 per hour for their time. Reimbursement for parking 
fees or RTC tickets will also be provided. 
 
Inclusion criteria: 
 
 Be between 60 and 90 years old. 
 Normal hearing or mild to moderate hearing loss (i.e., hearing thresholds between 25 and 
60 dB in both ears). 
 
Exclusion criteria:  
 
 
 Left-handed and ambidextrous (this is important to know given that handiness has been 
shown to influence speech perception); 
 Mother tongue not English (this is also important because of differences in speech 
perception between monolingual and bilingual individuals); 
 Language impairment (because this could be confounded with hearing impairment);   
 Dementia (as it can affect the understanding of task instructions and the ease of fitting 
devices); 
 Cerebrovascular diseases (as we study brain activity, and that can affect brain activity); 
 Untreated vision impairment (as it can affect the reading of task instructions); 
 Tinnitus and otologic disorders (as they can affect hearing); 
 Cochlear implants and hearing aids (as these devices are used to treat hearing loss); 
 Diagnosed addiction (alcohol or drugs) (as we study brain activity, and that can affect brain 
activity); 
 Significant medical or neurocognitive conditions (other than MCI) or interventions likely 
to significantly impact cognitive function (e.g., epilepsy, stroke, traumatic brain injury with 
loss of consciousness > 5 minutes, brain tumour, multiple sclerosis, hepatitis C, 
developmental delay, electroconvulsive therapy) (as we study brain activity, and that can 
affect brain activity); 

Study protocol 
 
4
 DSM-V diagnosis of major depressive disorder with active symptoms within 90 days of 
study entry, past or present psychosis, or other psychiatric disorders such as obsessive-
compulsive disorder, generalized anxiety disorder, and bipolar disorder (as we study brain 
activity, and that can affect brain activity). 
 
Study Protocol:  
 
This study will consist of two sessions of three hours separated by one week apart. This study will 
include hearing evaluations, auditory and cognitive tasks, and various questionnaires assessing 
health, anxiety, depression, and listening ability. 
 
In one session, participants will perform the auditory tasks without using any hearing devices, and 
in the other session, participants will be fitted, under laboratory supervision, with bilateral PSAPs. 
The order of the two sessions will be counterbalanced across participants so that some participants 
will complete the tasks with PSAPs in the first session and others in the second session. 
Counterbalancing will be generated by randomly assigning an order to each participant using the 
block randomization method (three blocks). 
 
In each session, participants will perform the same tasks. Cognitive assessment and pure-tone 
audiometry will be conducted only in the first session. 
 
In each session, the participant’s brain activity during the speech perception tasks will be 
recorded by electroencephalography (EEG) using a 76-channel Active Two acquisition system 
(BioSemi V.O.F., Amsterdam, The Netherlands). 
 
Clinical Trial Registration: 
 
Theoretically, this study meets the definition of a clinical study since we plan to evaluate the effects 
of a device on health outcomes. However, participation in this study involves fewer obligations 
than formal clinical studies. Participants will only wear the devices for one three-hour session, and 
no medication is applied. 
 
This clinical trial is registered here: https://www.clinicaltrials.gov/ct2/show/NCT05076045/.  
 
EEG Acquisition: 
 
During each session, participants will be fitted with a cap containing 76 specially designed sensors 
to monitor brain activity using an electroencephalogram. Sensors will also be placed on the cheeks 
and forehead. To record a good brain activity signal, we will need to abrade (i.e., scrape) a bit of 
the scalp at each sensor location. Then, the gel will be inserted into each sensor. Brain activity will 
be recorded during the speech perception task. The preparation for the EEG is about 1 hour. 
 
Participants may develop a headache or note some mild tenderness in the scalp area due to the 
placement of the brain-activity sensors. This occurs infrequently and is short-lasting. 
 
 

Study protocol 
 
5
Telephone Interview Questionnaires (≈ 45 minutes):  
 
1. Demographic and Health Questionnaire: This questionnaire will document demographic 
and health information. Information on age, gender, education level, country of birth, race, 
ethnicity, language, and health will be documented. This questionnaire will be completed 
with the participant during a telephone interview to assess eligibility. The duration of this 
questionnaire is approximately 30 minutes. 
 
2. The Edinburgh Handedness Inventory: This questionnaire is a measurement scale used to 
assess the dominance of a person's right or left hand in everyday activities. This 
questionnaire will be completed with the participant during a telephone interview to 
determine eligibility. The duration of this questionnaire is approximately 5 minutes. 
 
In-person Questionnaires (≈ 20 minutes): 
 
3. Speech, Spatial and Qualities of Hearing Scale (SSQ): This questionnaire measures self-
perception of hearing. It consists of 49 questions divided into three sections documenting 
hearing abilities in different daily life situations. The questionnaire includes 14 questions 
on speech-related hearing disabilities, 17 questions on spatial-related hearing disabilities 
and 18 questions on other hearing disabilities. For each question, participants will be asked 
to indicate on a scale of 0 to 10 if they would be completely unable (score of 0) or perfectly 
able (score of 10) to perform what is described in the question (e.g., understand speech in 
noise). The duration of this questionnaire is approximately 10 minutes. 
 
4. The 15-item Geriatric Depression Scale (GDS): This questionnaire is designed to detect 
symptoms of depression but is not used for diagnostic purposes. It consists of 15 yes/no 
questions about mood, aspirations, and daily activities. The duration of this questionnaire 
is approximately 5 minutes.  
 
5. The 10-item Geriatric Anxiety Scale (GAS): This questionnaire is designed to detect 
anxiety symptoms but is not used for diagnostic purposes. It consists of 10 questions that 
are answered with “Not at all,” “Sometimes,” “Most of the time,” and “All of the time.” 
The questions also concern mood, aspirations, and daily activities, focusing on anxiety. 
The duration of this questionnaire is approximately 5 minutes.  
  
Cognitive Assessment (≈ 20 minutes):  
 
1. Montreal Cognitive Assessment: General cognitive functioning will be assessed using the 
Montreal Cognitive Assessment Hearing Impaired (MoCA-HI), a 10-minute cognitive 
tool. This assessment measures several cognitive domains, including orientation, memory, 
visuospatial function, executive function, and language.  
 
Hearing Tests (≈ 15 minutes): 
 
1. Pure tone Audiometry: Pure tone audiometry will measure hearing. During this test, pure 
tones are sent through headphones into one ear and then into the other. This allows us to 

Study protocol 
 
6
determine the lowest intensity at which the sounds are perceived. Pure tone thresholds will 
be measured separately for both ears at the following frequencies: 250, 500, 1000, 2000, 
3000, 4000, 6000, and 8000 Hz. This test will take about 10 minutes. 
 
2. Quick Speech in Noise (QuickSIN) test: The QuickSIN test estimates speech-in-noise 
ability. Four sentences with five keywords per sentence are presented in four-talker babble 
noise. The sentences are presented at pre-recorded SNR ratios which decrease in 5-dB steps 
from 25 (very easy) to 0 (very difficult). The duration of this task is approximately 5 
minutes. 
 
Auditory Tasks (with EEG recording) (≈ 2 hours, including EEG preparation): 
 
1. Syllable discrimination task: The task is to discriminate pairs of syllables as identical or 
different in three intensities of background noise. The duration of this task is 
approximately 10 minutes. Three hundred syllable pairs will be presented, including 150 
identical and 150 different pairs. The task will be divided into three sections. For each 
section, participants will be asked to estimate the effort required to understand the words 
in the presence of background noise using a scale ranging from "no effort" to "extreme 
effort." Participants will be asked to respond using two keys on a computer keyboard. 
 
Statistical Analyses:  
 
The outcome of the QuickSIN is the signal-to-noise ratio (SNR) loss. Analyses will depend on the 
normality of the scores. Normal: Paired-sample t-test; non-normal: Wilcoxon signed rank test. 
 
The outcome measures for the syllable discrimination paradigm are reaction time and accuracy. 
We will use linear mixed-effects (LME) models separately for each dependent variable. Models 
will include Session (without, with) and SNR as within-subject factors. For self-reported listening 
effort, the listening effort score will be analyzed using a cumulative link mixed model.  
 
Regression models with health and demographic factors will be conducted to identify predictors 
of the benefits. 
 
Brain activity will be recorded using EEG. EEG recordings will be processed offline using Brain 
Electrical Source Analysis software (BESA 7.1). Measures of sensory-evoked response, event-
related potential and connectivity will be analyzed using BESA Statistics. 
 
Confidentiality: 
 
The research staff will collect and record in a research file only the information necessary for the 
proper conduct of the study. This information will remain strictly confidential and be kept under 
lock and key in the researcher's laboratory in charge of the research project. The data will be held 
for ten years. If participants withdraw their consent, the data will be destroyed immediately. To 
ensure confidentiality, the following measures will be provided: 
 

Study protocol 
 
7
 The name(s) and surname(s) of the participants will not appear on any report; 
 Participants’ names will be replaced by a code when signing the consent form. This code 
will be used on all research documents. Only research staff directly involved in the project 
will have access to the list of names and codes; 
 If the information obtained in this research is to be analyzed later, only the code will appear 
on the documents;  
 Under no circumstances will individual results be disclosed to anyone without the 
participants’ consent. 
 
Data Sharing: 
 
Participant data, such as behavioural measures and EEG recordings, will be shared on the Open 
Neuro 
platform 
(https://openneuro.org) 
or 
Scholars 
Portal 
Dataverse 
(https://dataverse.scholarsportal.info). Shared data will be further anonymized by replacing the 
participant code with a generic code. Participants will be informed of this sharing in the consent 
form. Participants will be able to withdraw their data from sharing if desired. Withdrawal from 
data sharing will not affect participation in the study. 
 
A summary of the results will also be published on https://www.clinicaltrials.gov. The participants 
will be informed in the consent form.  
 
Significance/Impact 
 
The results will also provide important new information on the effectiveness of PSAPs in 
addressing communication deficits of older adults with normal hearing and mild to moderate 
hearing loss. This will help provide guidelines for future low-cost device-based interventions for 
people who cannot afford conventional hearing aids and even more so for those at risk for cognitive 
impairment.