Evaluating the Clinical Effectiveness of a Community-based Hearing Aid Fitting Service Delivery Model Facilitated by Community Healthcare Workers (CHWs) Providing Smartphone-based In-situ and Pre-set Hearing Aid Fittings in Low- and Middle-income Communities (LMICs)
Phase: NA
Conditions: Hearing Loss
Sponsor: University of Pretoria

 
 
 
 
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 R33 PHASE STUDY:  PROTOCOL 
 
Evaluating the clinical effectiveness of a community-based hearing aid fitting service delivery 
model facilitated by CHWs providing smartphone-based in-situ and pre-set hearing aid 
fittings in low- and middle-income communities 
 
Document Approval 
Role 
Name 
Date 
Co-Principal Investigator 
De Wet Swanepoel 
 
Co Principal Investigator 
David R Moore 
 
Co Principal Investigator 
Lisa Hunter  
 
Co-investigator 
Herman Myburgh 
 
Co-investigator 
Marien A Graham 
 
Project Coordinator 
Tersia de Kock 
 
Research Coordinator 
Karina C De Sousa 
 
Research Coordinator 
Caitlin Frisby  
 
 
Document Version History 
This table should be updated with study-specific protocol revisions or amendments following 
feedback from any Ethics Committee. 
Version 
Date 
Description 
Responsible Person 
1.0 
2024-06-27 
First draft development  
Caitlin Frisby & Karina De Sousa 
2.0 
2025-01-17 
Second draft development 
Caitlin Frisby 
3.0 
2025-01-21 
Third draft development  
Caitlin Frisby 
4.0 
2025-02-03 
Fourth draft development 
Caitlin Frisby  
5.0 
2025-02-06 
Fifth draft development  
Caitlin Frisby  
6.0 
2025-02-25 
Sixth draft development 
Caitlin Frisby  
7.0 
2025-04-08 
Seventh draft development  
Caitlin Frisby  
8.0 
2025-04-22 
Eighth draft development 
Caitlin Frisby  
9.0 
2025-05-06 
Ninth draft development 
Caitlin Frisby 
10.0 
2025-06-17 
Tenth draft development 
Caitlin Frisby  

 
 
 
 
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Table of content 
1. 
List of Tables 
3 
2. 
List of Figures 
3 
3. 
Acronyms and abbreviations 
3 
4. 
Purpose 
4 
5. 
Responsibilities 
4 
6. 
Statement of compliance 
5 
7. 
General 
5 
7.1. 
Introduction 
5 
7.2. 
Sponsor details and investigational site(s) 
7 
8.3 
Investigational site(s) 
7 
8.4 
Description of the interventions used in experimental design 
7 
8.5 
Summary of the Clinical Investigation 
8 
8. 
Clinical investigation objectives 
8 
9. 
Clinical investigation design 
9 
10.1 Blinding 
11 
10.2 Randomization: 
13 
11. Ethical considerations 
13 
11.1 Informed consent 
13 
11.2 Reimbursement 
14 
11.3 Confidentiality 
14 
11.4 Validity and reliability 
15 
11.5 Follow-up 
15 
12. Participant population 
16 
12.1 Recruitment 
16 
12.2 Inclusion criteria 
16 
12.3 
Exclusion criteria 
17 
12.4 
Procedure for withdrawal 
17 
12.5 
Relationship between investigation population and target population 
17 
12.6 
Expected number of participants 
17 
13. Testing schedule and equipment 
18 
14. Statistical design and analysis 
21 
15.1 
Data management 
24 
15.1.1 
Data entry and collection 
24 
15.1.2 
Data quality control and validation 
25 
15.1.3 
Data privacy and retention policy 
25 

 
 
 
 
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15.1.4 
Data ownership and data sharing 
26 
15.1.5 
Audit trail 
26 
16. 
Adverse events and device defects/deficiencies 
26 
16.1 
Adverse events 
26 
16.2 
Serious Adverse Events (SAE) 
27 
16.3 
Adverse Device Effect (ADE) 
27 
16.4 
Device Deficiencies (DD) 
27 
16.5 
Adverse event reporting 
27 
17. 
Amendments and deviations to the protocol 
28 
17.1 
Protocol deviations & study violations 
29 
18. 
Dissemination Plan 
30 
19. 
References 
31 
 
1. 
List of Tables 
Table 1. 
Study Personnel. 
Table 2. 
Clinical trial equipment. 
Table 3. 
Adverse event criteria. 
 
2. 
List of Figures 
Figure 1. 
Proposed clinical trial design. 
 
 
3. 
Acronyms and abbreviations 
ADE 
 
 
Adverse Device Event 
AE 
 
 
Adverse Event 
AI 
 
 
Artificial-intelligence 
ANOVA 
 
Analysis of Variance 
CAPA  
 
Corrective and Preventive Action 
CHWs  
 
Community Healthcare Workers 
CIOMS  
 
Council for International Organizations of Medical Sciences 
CIP 
 
 
Clinical Investigation Protocol 
dB HL  
 
Decibel Hearing Level 
dB SPL  
 
 Decibel Sound Pressure Level 
DD 
 
 
Device Deficiency 
EC 
 
 
Ethics Committee 
GCP 
 
 
Good Clinical Practice 
HA 
 
 
Hearing Aids 
Hz 
 
 
Hertz 
IC 
 
 
Informed Consent  
IOI-HA  
 
International Outcome Inventory for Hearing Aids 
LMICs  
 
Low- and middle-income countries 
mHealth 
 
Mobile Health  

 
 
 
 
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NAL-NL2 
 
National Acoustic Laboratories - Non Linear Version 2 
POPIA  
 
Protection of Personal Information Act  
RCT 
 
 
Randomized Controlled Trial 
SAE 
 
 
Serious Adverse Event 
SNI 
 
 
Social Network Index 
SOP 
 
 
Standard Operating Procedure 
TMF 
 
 
Trial Master File 
 
4. 
Purpose 
The purpose of this study is to advance hearing care in low- and middle-income countries 
(LMICs) through the rigorous evaluation and optimization of innovative interventions and 
technologies. This study encompasses the following key aim: 
 
This study aims to establish the effectiveness of community-based hearing aid fittings 
facilitated by community healthcare workers (CHWs) using mobile health (mHealth) 
technologies in low- and middle-income communities (LMICs). The primary goal is to 
determine the efficacy of CHW-facilitated smartphone-based in-situ hearing aid (HA) fittings 
(a proprietary fitting based on the NAL-NL2 algorithm) and pre-set HAs fittings compared to 
minimal amplification through a single-blind randomized controlled trial (RCT). By comparing 
self-reported benefits between the experimental and control groups, this aim seeks to 
demonstrate the superiority of the CHW-facilitated smartphone-based and pre-set hearing aid 
fittings compared to minimal amplification. 
 
5. 
Responsibilities 
Table 1 describes the roles and responsibilities assigned to clinical research team members. 
 
 Table 1. Study personnel 
Role 
Name 
Responsibility 
Co-Principal Investigator 
De Wet Swanepoel 
Study planning, oversight, data analyses, 
and reporting 
Co-Principal Investigator 
David R Moore 
Study planning, oversight, data analyses, 
and reporting 
Co-Principal Investigator 
Lisa Hunter 
Study planning, oversight, data analyses, 
and reporting 
Co-investigator 
Herman Myburgh 
Study planning, technical oversight, data 
analyses, and reporting 
Co-investigator & Statistician 
Marien A Graham 
Study planning, technical oversight, data 
analyses, and reporting 

 
 
 
 
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Role 
Name 
Responsibility 
Site Coordinator 
Tersia de Kock 
Study planning, technical oversight, data 
collection, analysis, and reporting. Site 
coordinator for Khayelitsha and 
Drakenstein district  
Research Coordinator 
Karina De Sousa 
Study planning, technical oversight, data 
collection, data analyses, and reporting 
Research Coordinator & Site 
Coordinator 
Caitlin Frisby 
Study planning, technical oversight, data 
analyses, and reporting. Site coordination 
for Atteridgeville district 
6. 
Statement of compliance 
The clinical investigation has obtained the required approval from the Ethics Committee (EC) 
of the Faculty of Humanities at the University of Pretoria. Participants will be informed that 
their participation in the investigation is voluntary. Prior to any data collection, participants will 
sign a statement of Informed Consent (IC) that meets the requirements of local regulations 
and the Protection of Personal Information Act (POPIA). 
 
7. 
General 
7.1. 
Introduction 
Hearing loss is a significant global health issue, particularly in low- and middle-income 
countries (LMICs) (World Health Organization, 2021). In 2020, over half a billion people 
globally had a disabling hearing loss, with 1.5 billion experiencing mild-to-complete hearing 
loss in at least one ear (World Health Organization, 2021). The impact of hearing loss is 
especially severe in LMICs, where 90% of those with moderate to profound hearing loss 
reside, yet access to hearing health care is sparse to non-existent (Mulwafu et al., 2017; World 
Health Organization, 2021). In sub-Saharan Africa, hearing aid penetration is less than 3% 
among those who could benefit, starkly contrasting with the high prevalence and impact of 
hearing loss (Bisgaard et al., 2021). Globally, hearing loss ranks as the third leading cause of 
years lived with disability, underscoring the urgent need to address its impact on 
communication, cognition, education, employment, and social participation (World Health 
Organization, 2021). 
 
The World Health Organization (WHO) has outlined several strategies to improve global 
hearing health, including the use of innovative digital technologies and task-shifting by training 
community health workers (CHWs) (World Health Organization, 2021). The use of over-the-
counter hearing aids, such as pre-set device has also been recommended for LMICs (World 
Health Organization, 2021, 2024). Our study aligns with these strategies by focusing on 
scalable and sustainable methodologies in an LMIC context, specifically in South Africa. Our 
approach integrates CHW-facilitated testing, diagnosis, and intervention into a single holistic 
process, addressing common barriers such as loss to follow-up and ensuring the provision of 

 
 
 
 
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a paper-based hearing aid acclimatization and support programme to aid in hearing aid 
management and use.  
 
Study Aims 
This study aims to establish the effectiveness of community-based hearing aid fittings 
facilitated by community healthcare workers (CHWs) using mobile health (mHealth) 
technologies in low- and middle-income communities (LMICs). We hypothesize that 
amplification offered by smartphone-based in-situ hearing aid (HA) fittings and pre-set hearing 
aid fittings facilitated by CHWs have superior self-reported outcomes compared to minimal 
amplification.  
 
To test this hypothesis, we will conduct a single-blind randomized controlled trial (RCT) where 
participants are assigned to either the experimental smartphone-based in-situ hearing aid 
fitting, pre-set hearing aid fitting, or minimal amplification fitting. A minimal amplification fitting 
provides only the most basic level of amplification without individualized adjustments. This 
level of amplification is primarily intended to prevent occlusion effects rather than to offer 
meaningful hearing benefits. In this study, a flat 10 dB gain will be provided across frequencies 
regardless of the degree of hearing loss. A placebo-controlled design is essential for assessing 
the true effectiveness of hearing aid interventions beyond non-specific effects such as 
participant expectations or the general experience of wearing a device. Comparing 
experimental conditions to minimal amplification ensures that any observed benefits are 
attributable to the intervention rather than psychological or external influences.  
 
Outcomes will be measured by self-reported benefits, with control participants offered the 
smartphone-based in-situ fitting after six weeks. All participants will also receive a paper-
based hearing aid acclimatization and support programme on the day of the hearing aid fitting 
to assist them in hearing aid use and maintenance. The participants will also be provided a 
contact number for the CHWs to contact if any assistance is needed. 
 
Rationale  
Given the limited access to hearing care in LMICs due to prohibitive costs and scarcity of 
trained professionals, this study leverages mHealth solutions and task-shifting to CHWs as a 
sustainable and scalable approach. Preliminary studies have shown promising results for the 
components of these interventions, justifying the need for clinical trials to evaluate their 
effectiveness. By focusing on end-to-end smartphone-based in-situ hearing aid fittings and 
acclimatization support, this study aims to create an innovative and accessible model of 
hearing care that could significantly reduce the global burden of hearing loss. 
 
Additionally, understanding the difference in outcomes between meaningful amplification and 
minimal amplification is crucial for guiding hearing care strategies in LMICs. If substantial 
benefits are observed in the experimental groups relative to minimal amplification, it 
strengthens the case for scaling up CHW-facilitated hearing aid provision as a cost-effective 
solution. Conversely, if minimal amplification yields similar self-reported outcomes, it may 
suggest that additional interventions (e.g., counseling, expectations management) are 
necessary for maximizing hearing aid benefits in these settings. 
 

 
 
 
 
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7.2. 
Sponsor details and investigational site(s) 
Sponsor Name: National Institute of Deafness and Communication Disorders of the 
National Institutes of Health (NIH) 
Address: NIDCD Information Clearinghouse, 1 Communication Avenue 
Bethesda, MD 20892-3456, United States of America 
Funding source: Award Number R21DC019598 awarded to De Wet Swanepoel and David 
R. Moore; Research Funding 
8.3 
Investigational site(s) 
The clinical study will take place at three sites across two Provinces in South Africa. 
Community centres or homes (if participants do not have access to the community centre) 
across:  
1. Atteridgeville District, Gauteng, South Africa  
2. Khayelitsha District, Western Cape, South Africa 
3. Drakenstein District, Western Cape, South Africa 
 
8.4 
Description of the interventions used in experimental design 
Two different experimental devices will be used in this study. Namely the Lexie Lumens and 
the Go Ultras. These two devices each represent a different type of OTC hearing aid, self-
fitting in-situ and pre-set devices, respectively. These devices also have differences in terms 
of price, with the Go Ultras being the more low-cost option. Pre-set devices have also recently 
been recommended for use LMICs by the WHO (World Health Organization, 2021, 2024). 
This study will evaluate if one of the experimental devices has superior outcomes. Full details 
of the devices are reported below: 
 
The Lexie Lumens (Lexie Hearing) are self-fitting wireless air conduction hearing aids 
consisting of 16 channels, wide-dynamic-range compression technology, feedback reduction, 
Bluetooth connectivity and programming, digital noise reduction, and a directional microphone 
array. These hearing aids will be sourced at a cost of $240 USD per pair as this study will be 
conducted in low-income settings. The hearing aids allow for Bluetooth in-situ hearing aid 
fitting using the Lexie proprietary fitting algorithm that is based on the NAL/NL2 algorithm from 
a smartphone application (Lexie Hearing) based on the four hearing thresholds tested.  
 
These digital hearing aids were designed for use by adults over the age of 18 years with known 
or self-perceived mild-to-moderate hearing loss. The Lexie Lumens are behind-the-ear (BTE) 
hearing aids powered by replaceable batteries. Individuals can also conduct an in-situ hearing 
test via the hearing aids to allow for customized amplification. A research version of the 
application will be used to allow for either a customized in-situ fitting based on the NAL-NL2 
algorithm or a minimal gain (10 dB flat across frequencies regardless of degree of HL) fitting 
facilitated by the CHWs following the in-situ hearing test, also facilitated by the CHWs. A 
simple push of a button on the smartphone following an in-situ test will program the hearing 
aids on either the personalized setting or the minimal gain setting. These devices also have 4 
different listening environments, namely 1. Everyday use; 2. Noisy indoor; 3. Outdoor, and 4. 
Music.  
 

 
 
 
 
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Go Ultras (GoHearing) are rechargeable, BTE pre-set hearing aids with advanced audio 
features, digital sound processing and Bluetooth-streaming capabilities. Designed for adults 
with mild-to-moderate hearing loss, these hearing aids have four unique programs that the 
user can manually change to ensure optimal listening comfort. These devices have both 
program and volume memory functions, as well as noise and wind noise reduction. Go Ultras 
will be sourced at a cost of less than $130 USD per pair, as this study will be conducted in 
low-income settings. 
 
8.5 Summary of the Clinical Investigation 
Title: Evaluating the clinical effectiveness of a community-based hearing aid fitting service 
delivery model facilitated by CHWs providing smartphone-based in-situ and pre-set hearing 
aid fittings in low- and middle-income communities 
Purpose: To determine whether a community-based hearing aid fitting service delivery model 
facilitated by CHWs using mHealth technology to provide smartphone-based in-situ and pre-
set hearing aid fittings provide superior benefit for their users.  
Population: 90 participants over the age of 18 years (No maximum age) with mild-to-severe 
(20 to < 80 dB PTA in both ears) hearing loss. 
Design: Single-blind randomized controlled trial 
Initiation date: March 2025 
Completion date: October 2026 
 
8. 
Clinical investigation objectives 
The main aim of this project is to determine the effectiveness of a community-based hearing 
aid fitting service delivery model facilitated by CHWs, with the expectation that the 
interventions will prove superior to minimal gain. This study will investigate the effectiveness 
of a smartphone-based in-situ (proprietary algorithm based on the NAL-NL2 fitting) hearing 
aid fitting and pre-set hearing aid fitting in a three-arm, placebo-controlled single-blind 
randomized clinical trial. 
 
Primary endpoint hypothesis 
 
Primary Endpoint 
The primary endpoint of this study is the self-reported outcome measured using the IOI-HA 
global score at 6 weeks post-fitting. Outcome measures will also be captured at 12, 26, and 
52 weeks post-fitting. The endpoint assesses differences between study groups' overall 
hearing aid benefit and satisfaction. 
 
Superiority  
Null Hypothesis (H₀): There is no difference in the IOI-HA global score between the 
experimental and control groups (difference <3 points). 
 
Alternative Hypothesis (H₁): The IOI-HA global score for one or both experimental groups is 
superior to the control group by a margin of ≥3 points. 
 

 
 
 
 
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Non-inferiority (comparison of experimental groups) 
Null Hypotheses (H₀): Self-reported outcomes (IOI-HA) in the pre-set group are non-inferior 
to those in the smartphone-based in-situ fitting group, with the non-inferiority margin (δ₁) 
defined as 3.0 for the IOI-HA total score. 
 
Alternative Hypothesis (H₁): Self-reported outcomes (IOI-HA) in the pre-set group are inferior 
to those in the smartphone-based in-situ fitting group, exceeding the predefined non-inferiority 
margin for the IOI-HA total score (δ₁ = 3.0). 
Clinical Relevance 
A difference of ≥3 points in the IOI-HA score is considered clinically significant based on prior 
research by Apple, representing a meaningful improvement in hearing aid benefit, satisfaction, 
and quality of life. 
 
9. 
Clinical investigation design 
A randomized, three-arm, single-blind placebo trial (full blinding details below) with 90 
participants will be used. The estimated timeline for trial completion is approximately 52 weeks 
post-hearing aid fitting. The clinical trial will be conducted across three sites (Khayelitsha and 
Drakenstein Districts in the Western Cape Province of South Africa and Atteridgeville District 
in the Gauteng Province of South Africa). See Figure 1 below for a visual depiction of the trial 
design.  
 
Randomization (full details provided below) will be conducted before participant enrollment, 
ensuring that each participant is assigned to one of the three study arms (In-situ fitting, Pre-
set fitting, or Minimal Gain fitting) before enrolling in the study (full randomization details 
below). 
 
After baseline assessments to determine candidacy (T0), participants will be randomly 
assigned and start with one of the three interventions (T1). There will be one placebo-control 
group with Lexie Lumen hearing aids fitted to minimal gain (i.e., 10 dB HL across the frequency 
range regardless of hearing loss levels) with two experimental groups: (i) In-situ hearing aid 
fitting using a proprietary algorithm on Lexie Lumen hearing aids that are based on the 
National Acoustics Laboratories Non-Linear Version 2 (NAL-NL2) algorithm (ii) Pre-set 
hearing aid fitting with Go Ultra hearing aids. Following fitting (T1), there will be a 6-week field 
trial, with follow-up visits scheduled at 6 weeks (T2). Following that, the minimal gain group 
(control) will be crossed over to in-situ fitting (CG-T2; Figure 1), and another 6-week field trial 
will be conducted (follow up at CG-T3; Figure 1). Follow-up visits for the In-situ and Pre-set 
groups will occur again at 12 weeks (T3), 26 weeks (T4), and 52 weeks (T5).  
 
 
 
 
 
 
 
 

 
 
 
 
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Figure 1. Proposed clinical trial design. 
 
The primary endpoint will be at the six-week follow-up. The primary outcome measure will be 
the IOI-HA. A difference of ≥3 points in the IOI-HA score is considered clinically significant 
based on prior research by Apple, representing a meaningful improvement in hearing aid 
benefit, satisfaction, and quality of life. 
 
The secondary measures will be the RHHI-S,  EQ-5D-5L, and the Berkman-Syme Social 
Network Index (SNI). Baseline RHHI-S, EQ-5D-5L, and SNI scores will be compared with 
scores obtained at subsequent follow-up visits.  
 
Additionally, a questionnaire with Likert scale questions targeting functional use and 
meaningful life changes will be completed at all follow-up visits.  
 

 
 
 
 
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10.1 Blinding 
This trial incorporates a single-blind mechanism.  
 
• 
Experimental and Control Groups 
For the Experimental and Control groups, the Lexie Lumens hearing aids are programmed via 
an application after an in-situ hearing assessment. CHWs will use a custom-designed 
research version of the Lexie Hearing application to program the Lexie Lumens devices. Once 
the in-situ test has been completed, the app will present two fitting options: A or B. The app 
will prompt the CHWs to select either option A or B, corresponding to the in-situ fitting or the 
minimal gain setting (10 dB gain across frequencies). A third party (administrative assistant) 
observing the session will ask the CHW to select fitting A or B to achieve the respective 
intervention settings. Only the third party will know if the A or B indicates the in-situ fitting or 
minimal gain option. This setup ensures that the participants remain unaware of the allocation. 
 
The app interface will not display or provide any information about these settings, ensuring 
that participants are blind to the intervention applied. The programming process will be 
identical in appearance and duration for both options, minimizing potential clues. 
 
Participants will be fitted with hearing aids but not informed about the specific programming 
applied or told that other participants may have different program settings. No visible or 
functional differences will distinguish the two settings for the participant. Additionally, these 
hearing aids come with four listening environments, and CHWs will assist participants in 
selecting the environment they feel most comfortable with. 
 
• 
Pre-set Group 
In the Pre-set group, participants will receive Go Ultra hearing aids, which differ from the Lexie 
Lumens devices used in the other arms. These hearing aids come with four pre-set programs, 
and CHWs will assist participants in selecting the program they feel most comfortable with. 
This will be done by allowing the participants to experience listening on all four programs 
through a conversation with the CHW. The participant will also be taught how to change the 
program if they later feel another program would be more suitable. CHWs will record the 
program selected at all subsequent follow-up visits. Participants will remain blinded to the 
existence of other intervention groups and their respective programming methods. 
 
CHWs will facilitate the selection of one of the four pre-set programs based on participant 
feedback about comfort and sound quality. Since CHWs directly engage in program selection, 
they will be aware that this group receives a different intervention than the Experimental and 
Control groups. 
 
Participants will not know the specifics of the other groups or the nature of their own 
intervention beyond the hearing aid they receive. Efforts will be made to avoid any 
communication or behavior from CHWs that might suggest differences in treatment across 
groups. 
 

 
 
 
 
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A transparent yet neutral approach will be taken in communication with control group 
participants. They will be informed that the purpose of the study is to evaluate different hearing 
aid settings to determine which settings work best for them.  Specific details about their initial 
device settings will not be disclosed, but the CHWs will explain that their settings will be 
changed in six weeks. The CHWs will state that we are not sure which settings will work best 
for them and emphasize the importance of their honest feedback. Participants will be 
encouraged to share their experiences openly, including what they liked or did not like about 
their settings. This approach ensures that they feel involved in the process while maintaining 
blinding integrity. 
These two different experimental devices were selected as they represent two types of over-
the-counter (OTC) hearing aids, self-fitting in-situ and pre-set devices, respectively. These 
devices also have differences in terms of price, with the Go Ultras being the more low-cost 
option. This study will evaluate if one of the experimental devices has superior outcomes.  
 
Maintaining Blinding Integrity 
CHWs will undergo thorough training to ensure they follow standardized procedures for 
programming and assisting participants and avoid making comments that might reveal 
allocation details to participants. 
 
Participants will receive uniform instructions and explanations about the study to prevent them 
from realizing that there are different group allocations. They will be informed that all devices 
are designed to improve hearing, but will not be told about the differences in programming 
methods or devices. 
 
To maintain blinding integrity, all hearing aid devices will be repackaged into identical, 
unbranded packaging before distribution to participants. This ensures that differences in 
original device packaging do not inadvertently reveal group allocation. By standardizing the 
appearance of all devices, we minimize the risk of participants perceiving any distinctions 
between intervention groups, thereby preserving the study’s single-blind design. 
 
App Design for Lexie Lumens: 
The app will feature a streamlined interface without visual or contextual cues indicating the 
programmed settings. CHWs will be instructed to follow app prompts without questioning or 
deviating from the process. 
 
Standardization Across Groups: 
All participants will follow the same study schedule, including fitting sessions, follow-ups, and 
assessments. Any study materials provided to participants will be identical in format and 
content, irrespective of group allocation. CHWs will be provided with a checklist and script to 
ensure they do not inadvertently provide information to the participants that could reveal group 
allocation.  
 
Challenges and Mitigation Strategies 
 
Cross-Group Communication: 

 
 
 
 
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Participants may discuss their experiences with others, risking unintentional unblinding. To 
mitigate this, participants will be advised not to share details about their devices or 
experiences until the study concludes. 
 
10.2 Randomization: 
Randomization will be conducted before participant enrollment to minimize bias and maintain 
balance across the study arms. A total of 90 participants (30 per arm) will be recruited across 
three data collection sites. Randomization will be implemented using a pre-generated 
sequence and managed via a centralized Google Sheet system to streamline and secure the 
process. 
 
Permuted block randomization with a block size of 3 will be used. This method ensures that 
each of the three study arms—“In-situ,” “Control,” and “Pre-set”—receives an equal number 
of participants throughout the enrollment process while preventing predictability in participant 
assignments. Within each block, participants will be randomly allocated to one of the three 
arms, maintaining allocation concealment. 
 
For example, in a block of 3 participants, one will be assigned to each arm. The order of 
assignments within each block will be randomized, ensuring no predictable patterns. The 
randomization will be carried out using a secure software tool or random number generation 
process such as the online tool Sealed Envelope (https://www.sealedenvelope.com/simple-
randomiser/v1/lists), with the final sequence stored securely. 
 
The final allocation sequence will be determined before the study commences to ensure 
blinding, preserving the integrity of the trial. Once a participant is deemed eligible by the 
community healthcare worker (CHW), the site administrator will enter their details into the 
predetermined Google Sheet to assign them to their allocated arm. 
 
11. Ethical considerations 
The proposed clinical trial has obtained ethical approval from the University of Pretoria 
Humanities Research Ethics Committee. The protocol will also be registered on 
Clinicaltrials.gov.  
 
11.1 Informed consent 
Informed consent ensures adherence to the ethical principle of autonomy, ensuring that the 
individual makes their decisions freely and independently to partake in the study (DoH, 2020). 
Study personnel will receive training on the Informed Consent Form (ICF) (Appendix X) and 
the ICF Standard Operating Procedure (ICF-SOP) prior to study initiation. All training will be 
logged and recorded within the Site Master File (SMF), and if there are any changes to the 
ICF process, all study personnel will be retrained.  
 
A CHW will discuss and inform the individual about the study to determine their willingness to 
participate and obtain written informed consent from the participant. The ICF and consent 
process will be offered to the individuals in English, isiXhosa, or Sepedi. All individuals willing 
to participate in the clinical study will be informed to the fullest extent possible about the study 
in terms that they are able to understand. All individuals willing to participate in the clinical 

 
 
 
 
Page 14 of 32 
 
 
investigation will have an opportunity to ask questions about the study to ensure that they 
have a complete understanding of what their participation would entail.  
 
All individuals will be informed that their participation is voluntary and they can withdraw from 
the study at any time without penalty. They will be required to personally sign the ICF, which 
will include a statement that meets the requirements of local regulations and the Protection of 
Personal Information Act (POPIA). The ICF will also be signed and dated by the person 
responsible for obtaining informed consent from the individual. A copy of the ICFs will be 
provided to the participant, and a signed copy will also be filed with the participant’s source 
documentation. Should the individual be illiterate, an impartial witness will be asked to sign 
and date the ICF on behalf of the individual after verbal consent has been obtained.   
The Ethics Committee of the Faculty of Humanities at the University of Pretoria has reviewed 
and granted approval. (Appendix X).  
 
Topics covered in the ICF include:  
 
● A description of the clinical investigation  
● Information regarding their voluntary participation 
● Potential risks and discomforts 
● Benefits to participation 
● Alternative procedures or treatments 
● Confidentiality 
● Data collection and sharing of results  
● Conditions of termination of participation  
● Reimbursement 
● Compensation in the event of a trial-related injury  
● Contact details 
If any updates or revisions are made to the currently approved version of the ICF, the revised 
version will be re-approved by the EC, and re-consent will take place to ensure the participant 
is aware of the changes made and agrees to continue to participate in the study. The ICF-
SOP (doc number xxx) provides an in-depth overview of the procedure discussed above. 
11.2 Reimbursement 
Study participants will not be reimbursed for participation in the study. All participants will have 
their hearing assessed free of charge by trained CHWs. All participants who are eligible to 
receive hearing aids will be able to keep their hearing aids free of charge upon completion of 
the study. All participants using the Lexie Lumen devices will be provided with batteries for the 
duration of the study (batteries to be provided until the 52 week follow-up post fitting). 
11.3 Confidentiality 
All participant records and results will be coded alpha-numerically to ensure adherence to the 
ethical principle of confidentiality. No identifying information or results will be made known in 
the data analysis or reporting process to allow others to become aware of a specific 
participant’s identity. Information regarding confidentiality will also be contained in the ICF 
(Appendix XXX). The research team members and CHWs will know the identity of the 

 
 
 
 
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participants. However, a participant code will be assigned to each participant so that the data 
captured, recorded, stored, and reported remains anonymous. 
 
The data will be kept in hard copy in the Trial Master File (TMF) for a period of 10 years and 
will also be stored electronically in a password-protected Excel spreadsheet that only the 
research team will have access to. This electronic version will also be stored for a period of 
10 years as per the University of Pretoria's data management policy. The results obtained 
from the research study will be recorded anonymously and reported honestly and as 
accurately as possible.  
11.4 Validity and reliability 
Validity determines if the measurements are accurate and whether they are measuring what 
they intend to measure (Portney, 2020). To ensure validity, all baseline measurements will be 
conducted in the same manner by trained CHWs. The CHWs all have the same training on 
the equipment. A refresher training session that covers equipment use and study procedures 
will be done prior to data collection commencement. Training for all participating CHWs will 
be recorded on the trial training log (Appendix X).  Testing will be done using the same 
standard of equipment at each site, which will be calibrated according to the necessary 
regulations before any testing is conducted. To enhance validity, each participant will have 
multiple follow-up visits at set intervals (Figure 1 above) to provide accurate feedback about 
their experience with each of the devices.  
 
Reliability describes the consistency of measurement or correlation between repeated 
observations or measurements (Irwin et al., 2018). To ensure reliability, the study protocol will 
remain the same for each participant where possible. During the baseline and follow-up visits, 
standardized questionnaires will be used to assess participants' subjective experiences with 
the hearing aids. Using standardized, validated questionnaires ensures consistency in the 
measurement of subjective experiences across all participants and visits. Consistency in the 
questions and response options helps in obtaining reliable and consistent data over time, 
improving the reliability of the study.  
 
11.5 Follow-up 
The following follow-ups will be needed where participants will complete self-reported outcome 
measures: 
● 6 weeks (cross-over for Control Group) 
● 12 week 
● 26 weeks (both Experimental groups; not specifically part of the RCT, but we plan to 
continue follow-ups for longitudinal data) 
● 52 weeks (both experimental groups; not specifically part of the RCT, but we plan to 
continue follow-ups for longitudinal data) 
 

 
 
 
 
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12. Participant population 
12.1 Recruitment 
Participants will be recruited using a self-report or community referral mode of hearing loss 
detection and snowball sampling within communities (Leedy & Omrod, 2015). Community 
healthcare workers from the hearX Foundation (also residing in the communities) will contact 
leaders of various community networks such as community NGOs, elderly groups, and 
religious groups to explain and create awareness of the study. Interested individuals will be 
provided with the CHW's contact details, and they will then have the opportunity to contact the 
CHWs for more information. CHWs will also conduct awareness talks at various community 
networks such as community NGOs, elderly groups, and religious groups to inform community 
members of the study. Participants will be selected from such individuals who indicate their 
availability to be part of this study and grant permission to be included as participants. The 
participants' contact details will be kept strictly confidential, and only the CHWs will have 
access to these details. 
Power: Sample size calculations for this three-arm experimental study, involving four 
repeated measures (baseline and follow-up assessments at 6, 12, 26, and 52 weeks), were 
performed using the GLIMMPSE software (GNU General Public License, version 2). 
GLIMMPSE is specifically designed to compute sample size and statistical power for 
Generalized Estimating Equations (GEE), which are particularly suited for longitudinal and 
repeated measures data where observations within participants are correlated. In this study, 
GEE was deemed appropriate because it accounts for the within-subject correlations across 
multiple time points, ensuring more accurate and robust estimates for group effects. The 
calculations focused on the primary outcome, IOI-HA, and were designed to detect a medium 
effect size (d = 0.5; Cohen, 1969) with at least 80% statistical power. It is widely acknowledged 
that determining sample sizes to detect small effect sizes is often unnecessary, as such 
effects, while potentially statistically significant (p ≤0.05), may lack practical or real-world 
relevance (Baicus & Caraiola, 2009; Peeters, 2016). Consequently, this study prioritized the 
detection of at least a medium effect size. The analysis indicated that a total of 69 participants 
(23 per arm) would be sufficient to achieve a statistical power of 0.811, assuming a Type I 
error rate of 0.05. The sample size calculation employed the Hotelling-Lawley Trace test and 
incorporated a correlation matrix with decreasing correlations over longer time intervals 
between measurements. 
12.2 Inclusion criteria 
Consenting adults fulfilling the following criteria will be recruited for the clinical trial: 
● 18 years and older  
● Confirmed mild to severe (20 to < 80 dB PTA in both ears; (World Health Organization, 
2021)) hearing loss (determined during baseline assessments) 
● Willing/available to commit to at least 6- and 12-week follow-ups 
 
The inclusion and exclusion criteria form will be completed to keep a record of all the 
individuals who have met the criteria and are included in the clinical investigation. Records will 
also be kept in the TMF.  
 

 
 
 
 
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12.3 
Exclusion criteria 
● Younger than 18 years 
● Hearing loss too severe (≥80 dB HL PTA) 
● Normal hearing (<20 dB HL PTA)  
● Middle ear pathology such as otitis media; active drainage from the ears. 
● Unwilling/unavailable to commit to at least 6- and 12-week follow-ups. 
● Unilateral hearing loss 
 
The inclusion and exclusion criteria form will be completed to keep a record of all individuals 
who meet the criteria and those who were excluded from the study. The investigational devices 
are designed for a set criteria of individuals, hence the specific exclusion criteria that have 
been set out to ensure that the results/ feedback from the clinical investigation are able to be 
generalized to the appropriate population and relevant claims made to be appropriate.  
12.4 
Procedure for withdrawal 
Individuals have the right to withdraw from the study at any point in time without any negative 
or adverse consequences. All participants who are enrolled in the clinical trial will be recorded 
on the screening and enrollment log form after ensuring that they meet all the inclusion criteria. 
Participants will be withdrawn from the study when/if it is deemed that there are any risks 
associated with the use of the  devices. These events/risks will be documented on the Adverse 
Events (AE) or Serious Adverse Events (SAE) form, and actions taken will be logged so that 
there is a record of the duration of participation in the clinical trial.  
 
All individuals enrolled in the clinical trial will be recorded in the enrollment log. Should there 
be participants who are lost to follow-up, the researchers will try to contact them. Should they 
be unreachable, the details will be documented with their case report forms, including the 
duration of their participation in the study, the reason for exclusion/lost-to-follow-up, and 
methods used by the researchers to follow up with them.  
 
The clinical study aims to enroll 90 participants. If a large number of participants withdraw from 
the study, resulting in minimal information being collected to substantiate the clinical results, 
then recruitment and enrollment of new individuals need to be considered.  
 
12.5 
Relationship between investigation population and target population 
The population that most often requires access to community-based hearing aid fitting 
services are individuals 18 years of age or older with self-perceived or confirmed mild to 
moderate hearing loss. Therefore, as mentioned above, the selected adults who meet the 
outlined inclusion and exclusion criteria are representative.  
 
12.6 
Expected number of participants 
This study will aim to enroll 90 participants (30 in each arm) using a single-blind, randomized 
controlled study design. The participants will be divided into three groups and randomized into 
either the In-situ (smartphone-based proprietary fitting based on NAL-NL2), Control (minimal 
gain amplification), or Pre-set group. The control group will make use of their treatment option 
for a period of six weeks. Thereafter, they will cross over and receive the In-situ treatment 

 
 
 
 
Page 18 of 32 
 
 
option for a period of six weeks. The In-situ and Pre-set groups will make use of their 
designated treatment option for the entire duration of the study.  
 
13. Testing schedule and equipment 
Table 2 below details the equipment that will be used during the clinical trial. 
 
Table 2. Clinical trial equipment 
Equipment  
Description 
hearScopeTM (HearX Group, 
Pretoria, South Africa)  
The trained CHWs will perform otoscopy to inspect the outer ear 
to identify any possible ear disease (e.g., wax impaction, 
perforation, or ear infection) and to evaluate the patency of the ear 
canal to accommodate a hearing aid. These images can be 
reviewed by an AI imaging classification on the video-otoscopy 
application. These images are also uploaded onto a secure 
mHealth cloud-based data management platform where a 
professional team (audiologists and ENT) can remotely review the 
images and assist the CHWs in determining participant eligibility. 
hearTestTM (HearX Group, 
Pretoria, South Africa) 
CHWs will facilitate hearing assessments using the hearTest. Pure 
tone air conduction thresholds at 500, 1000, 2000 and 4000 Hz 
will be determined. Participants will be asked to respond (i.e., 
raising their hand) every time they hear a tone, even when the 
tones become softer. (Sennheiser HD280 Pro headphones 
calibrated 
according 
to 
International 
Organization 
for 
Standardization 389-1 [ISO] 2013 and International Organization 
for Standardization 389-9 [ISO] 2014 standards). These results 
are also uploaded onto a secure mHealth cloud-based data 
management platform where a professional team (audiologists 
and ENT) can remotely review and assist the CHWs in determining 
participant eligibility. 
Lexie Lumen Hearing aids 
(Lexie Hearing) 
Lexie Lumen hearing aids (left and right pair) in non-identifying 
packaging, including the user manual, domes (tulip, open and 
double of different sizes), cleaning kit and measuring tool. 
Go Ultra Hearing aids (Go 
Hearing) 
Go Ultra hearing aids (Left and right pair) in non-identifying 
packaging, including user manual, domes (small, medium, large - 
open and closed), slim tubes (various sizes), slim tube measuring 
tool, cleaning kit, and charger.  
International Inventory for 
Hearing Aids (IOI-HA) 
The IOI-HA is a validated seven-item questionnaire to measure 
the effectiveness of the hearing aid intervention (Cox and 
Alexander, 2002). It targets seven domains including, (i) daily use, 
(ii) benefit, (iii) residual activity limitations, (iii) satisfaction, (iv) 
residual participation restrictions, (v) impact on others, and (vi) 
quality of life. Each item has five response choices, from worst to 
best outcome (Appendix XXX). The IOI-HA has been translated to 
the languages most commonly used in these communities namley 

 
 
 
 
Page 19 of 32 
 
 
isiXhosa and Sepedi. The participants will have the option to 
complete the IOI-HA in either of these languages or in English. 
Revised Hearing Handicap 
Inventory and Screening Tool 
(RHHI-S)  
The RHHI-S is a validated 10-item questionnaire that is a strong 
unidimensional, clinically informative measure of self-perceived 
hearing handicap that can be used by adults of all ages 
(Cassarly, Matthews, Simpson, & Dubno, 2020). Each question 
has three possible responses, including yes, sometimes, or no. 
The RHHI-S has been translated into the languages most 
commonly used in these communities, namely isiXhosa and 
Sepedi. The participants will have the option to complete the 
RHHI-S in either of these languages or in English. (Appendix XX) 
EQ-5D-5L 
The EQ-5D-5L is a standardized instrument developed by the 
EuroQol Group to assess health-related quality of life. It consists 
of a Descriptive System. This covers five dimensions—mobility, 
self-care, 
usual 
activities, 
pain/discomfort, 
and 
anxiety/depression—each with five levels of severity (from "no 
problems" to "extreme problems"). The respondent selects one 
level in each dimension, resulting in a 5-digit health state profile 
(e.g., 1-2-3-1-1) (Herdman et al., 2011). Each 5-digit health state 
profile is converted into a single index value (utility score) using a 
country-specific value set. The utility score reflects the individual’s 
overall health status, where 1 = full health, 0 = dead, <0 = states 
worse than death. The EQ-5D-5L has been translated into the 
languages most commonly used in these communities, namely 
isiXhosa and Northern Sotho (Sepedi). The participants will have 
the option to complete the EQ-5D-5L in either of these languages 
or in English. (Appendix XX) 
Berkman-Syme Social Network 
Index (SNI)  
The Berkman-Syme Social Network Index (SNI) is a well-
established tool used to assess the extent of an individual's social 
connections. The SNI examines the relationship between social 
networks and health outcomes. The SNI evaluates social 
integration by assessing four key domains: Marital status – 
Whether the individual is married or in a committed partnership. 
Contacts with close friends and relatives – Frequency of social 
interactions with family and friends. Religious group membership 
– Whether the individual is part of a church or religious group and 
attends regularly. Participation in voluntary or community 
organizations – Involvement in social or civic groups outside of 
family and work. 
The SNI assigns points based on the individual's responses to the 
above components. Scores range from 0 to 4, with higher scores 
indicating greater social integration. 
Non-standardised 
Questionnaire 
A non-standardized questionnaire will be included to obtain 
information from the participants on their perceptions of the 

 
 
 
 
Page 20 of 32 
 
 
hearing aids. This includes Likert scale and open-ended 
questions. (Appendix XX) 
 
Procedure – All assessment and fitting procedures will be facilitated by the CHWs 
T0: Baseline assessment 
● Assess participants for candidacy 
● Obtain Informed Consent from the participants 
● Record demographic information 
● Complete the baseline EQ-5D-5L, SNI, and RHHI-S  
● Conduct otoscopy 
● Conduct audiometric evaluation to ensure that participants meet the pure tone air-
conduction thresholds to be included.  
● The clinical research audiologists will then establish candidacy by reviewing the 
otoscopy and PTA results. The eligible participants will be randomly allocated to either 
the In-situ, Control, or Pre-set group. Randomization will be conducted before 
participant enrollment, ensuring that each participant is assigned to one of the three 
study arms (Lexie Lumen with in-situ fitting, Go Ultra with Pre-set fitting, or Minimal 
Gain) before enrolling in the study. A random number generator will allocate participant 
numbers to the respective arms. As soon as a participant is enrolled, they will 
automatically be assigned to one of the three arms based on the predefined 
randomization process. This approach ensures unbiased group allocation from the 
outset of the study. This randomization will be done by an additional independent party. 
 
T1: Hearing-aid fitting 
Once randomized into one of the three groups, participants will be booked for Visit 2 for 
hearing aid fitting. All participants will undergo otoscopy, and the participants (not the pre-set 
group) will undergo an in-situ hearing test via the Lumen hearing aids before the hearing aid 
fitting.  
 
In-situ Group 
● The CHW will fit each participant in the in-situ group with the Lumens programmed 
using the smartphone-based in-situ (proprietary algorithm based on the NAL-NL2) 
fitting.  
● Participants will select the listening environment they feel most comfortable with.  
 
Control Group 
● Participants in the control group will be fitted with Lumens programmed using minimal 
gain (10 dB gain across frequencies regardless of degree of HL). This will be 
conducted by the CHW.  
● Participants will select the listening environment they feel most comfortable with.  
 
Pre-set Group 
● The CHW will fit each participant in the pre-set group with Go Ultra hearing aids on 
one of the four pre-set programs. Participants will select the program they feel most 
comfortable with.  

 
 
 
 
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T2: Follow-up #1 and cross-over for Control Group 
● After 6 weeks of hearing aid use, participants from all groups will return for a follow-up 
assessment.  
● The International Outcome Inventory for Hearing Aids (IOI-HA), the Revised Hearing 
Handicap Inventory – Screening (RHHI-S), EQ-5D-5L, SNI, and a non-standardized 
questionnaire will be completed by the participants.  
● The control group will then be offered the in-situ intervention (proprietary in-situ fitting 
based on NAL-NL2). 
● An administrative assistant will collect outcome measures to avoid CHW bias. 
 
T3: Follow-up #2 (Final follow-up for Control Group) 
● After 12 weeks of hearing aid use, all participants will return for a follow-up 
assessment.  
● The International Outcome Inventory for Hearing Aids (IOI-HA), the Revised Hearing 
Handicap Inventory – Screening (RHHI-S), EQ-5D-5L, SNI, and a non-standardized 
questionnaire will be completed by the participants.  
● An administrative assistant will collect outcome measures to avoid CHW bias. 
 
T4: Follow-up #3  
● After 26 weeks of hearing aid use, only participants from the Experimental groups will 
return for a follow-up assessment.  
● The International Outcome Inventory for Hearing Aids (IOI-HA), the Revised Hearing 
Handicap Inventory – Screening (RHHI-S), EQ-5D-5L, SNI, and a non-standardized 
questionnaire will be completed by the participants.  
● An administrative assistant will collect outcome measures to avoid CHW bias. 
 
T5: Final Review   
● After 52 weeks of hearing aid use, only participants from the Experimental groups will 
return for a follow-up assessment.  
● The International Outcome Inventory for Hearing Aids (IOI-HA), the Revised Hearing 
Handicap Inventory – Screening (RHHI-S), EQ-5D-5L, SNI, and a non-standardized 
questionnaire will be completed by the participants.  
● An administrative assistant will collect outcome measures to avoid CHW bias. 
 
14. Statistical design and analysis 
Data analysis will be conducted using IBM Statistical Packages of the Social Sciences (SPSS 
v30.0, Chicago, Illinois). Figures will be completed in R (v 4.3.2; R Core Team, 2023).  
Design: This is a single-blind randomized control trial. This trial will have a control group. Two 
of the three groups receive the experimental hearing aid algorithm during the trial. The control 
group receives the in-situ hearing aid fitting immediately after the trial if, as hypothesized, it is 
effective. The challenges are limitations in the sensitivity of the outcome measures, inability 
fully to blind the pre-set group. 
Statistical tests: 

 
 
 
 
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Firstly, data cleaning will be done. This process involves fixing or removing incorrect data 
(which could be due to data capturing errors) and fixing incorrectly formatted data. Following 
data cleaning, a missing value analysis will be conducted. There are four different types of 
missing data that are generally categorised, namely, missing completely at random (MCAR), 
missing at random (MAR), missing not at random (MNAR), and structurally missing data. The 
type of missing data dictates how it should be handled. Following the missing values analysis, 
descriptive statistics such as measures of location (mean, median) and measures of spread 
(standard deviation, interquartile range) and counts (frequencies, percentages) will be 
extracted. For continuous variables, normality will be tested for using the Shapiro-Wilk test. 
The Shapiro-Wilk test will be used for this purpose as opposed to the more well-known 
Kolmogorov-Smirnov test, as the Shapiro-Wilk test is known to have more power in detecting 
differences from normality (Field, 2024). For correlational analysis, the parametric Pearson 
correlation (if normal) or the nonparametric Spearman (if non-normal) will be used. To test for 
differences in biographical data, for differences between two independent groups, say, 
between male and female, the parametric independent samples t-test (if normal) or the 
nonparametric Mann-Whitney test (if non-normal) will be used. In the case where there are 
three or more independent groups, the parametric ANOVA test (if normal) or the 
nonparametric Kruskal-Wallis (if non-normal) will be used. For all statistical tests, a 5% level 
of significance will be used. 
The IOI-HA, RHHI-S, SNI, and EQ-5D-5L will be outcome measures in these trials. For all 
these instruments, the respondents will be asked to respond by marking the response which 
most accurately represents their situation as they perceive it. Descriptive statistics will be 
computed, and measures of location (mean if normal, median if non-normal) and measures of 
variability (standard deviation if normal, interquartile range if non-normal) will be reported. 
Pearson correlations (if normal) or Spearman correlation (if non-normal) will be used to 
calculate correlations. For example, the number of problems respondents experience with 
their hearing aids will be correlated with satisfaction and benefit. Comparisons between groups 
will be made, for example, for differences in satisfaction and benefit between males and 
females, the independent samples t-test (if normal) or the Mann-Whitney test (if non-normal) 
will be used. The independent samples t-test and Mann-Whitney tests are used to test for 
differences between two unrelated/independent groups. For three or more groups, the one-
way ANOVA test (if parametric) and the Kruskal-Wallis test (if non-normal) will be used. 
The IOI-HA has seven items concerned with the use of hearing aids, covering the benefits 
perceived, remaining activity limitation, satisfaction, residual participation restriction, effect on 
significant others, and change in quality of life. The response data will be checked for normality 
using the Shapiro-Wilk test. If the response data is normally distributed, then parametric tests 
will be used, and, on the other hand, if the response data differs significantly from normality, 
nonparametric tests will be used. Descriptive statistics will be computed, and measures of 
location (mean if normal, median if non-normal) and measures of variability (standard 
deviation if normal, interquartile range if non-normal) will be reported. Kendall's tau, which is 
a nonparametric measure of relationships between ranked data, will be used to compute the 
intercorrelation of the seven questions (Stephens, 2002). The results from the intercorrelations 
will be supported by a principal component analysis which will be used to identify factors. This 
is in line with several studies that have applied factor analysis on the IOI-HA, showing that the 
responses can be described by two main factors (Arlinger et al., 2017). Factor 1 represents 
use, benefit, satisfaction, and quality of life (i.e., Items 1, 2, 4, and 7), whereas Factor 2 
represents residual activity limitations, residual participation restrictions, and impact on others 
(i.e., Items 3, 5, and 6) (Arlinger et al., 2017). Factor 1 (typically referred to as "me and my 
hearing aids"), Factor 2 (typically referred to as "me and the rest of the world") and the mean 
IOI-HA total scores will be related to the demographic questions (age, gender, degree of 
hearing loss) using correlations and tests for differences. For the latter, these comparisons 

 
 
 
 
Page 23 of 32 
 
 
between, say, males and females, will be done using the independent samples t-test (if 
normal) or the Mann-Whitney test (if non-normal). The independent samples t-test and Mann-
Whitney tests are used to test for differences between two unrelated/independent groups. For 
three or more groups, the one-way ANOVA test (if parametric) or the Kruskal-Wallis test (if 
non-normal) will be used. The mean IOI-HA total score, the mean IOI-HA total score for Factor 
1 and the mean IOI-HA total score for Factor 2 will be represented as a function of average 
hearing thresholds (PTA; 0.5, 1, 2, and 4 kHZ), respectively (Arlinger et al., 2017). Scatterplots 
with mean IOI-HA total scores (vertical axis) as a function of PTA (horizontal axis) will be 
created, and second-order polynomial regression lines will be fit to these figures, which will 
assist with interpreting relationships. Say, for example, the curve has a slightly concave 
downward shape, then clients with very mild hearing loss reported very high mean scores. 
Logistic regression models will also be built. For example, the first question of the IOI-HA 
instrument asks about, on an average day, how many hours a respondent used their hearing 
aid(s). The options are 'none', 'less than 1 hour a day', '1 to 4 hours a day', '4 to 8 hours a day', 
'more than 8 hours a day'. Logistic regression can be utilised to assess predictors (age, 
gender, degree of hearing loss) associated with the non-regular use of hearing aids (Aazh et 
al., 2015).  
For the RHHI-S, there are ten questions that are scored 0 = “No”, 2 = “Sometimes”, 4 = “Yes”, 
that assess how an individual perceives the social and emotional effects of hearing loss with 
questions such as “Does a hearing problem cause you to feel embarrassed when meeting 
new people?”, and “Do you have difficulty hearing when someone speaks in a whisper?”. The 
score can range from a minimum of 0 (if a respondent answers “no” to all ten questions) and 
a maximum of 40 (if a respondent answers “yes” to all ten questions). The values are 
interpreted as follows: 0-8 (suggest no hearing handicap), 10-24 (suggest mild-moderate 
hearing handicap), 26-40 (suggest significant hearing handicap) (Mccabe, 2019). The scores 
will be related to the demographic questions (age, gender, degree of hearing loss) using 
correlations and tests for differences. As explained above, the tests for differences between 
two unrelated/independent groups will be conducted using the independent samples t-test (if 
normal) or the Mann-Whitney test (if non-normal). For three or more groups, the one-way 
ANOVA test (if parametric) or the Kruskal-Wallis test (if non-normal) will be used. Scatterplots 
with RHHI-S scores (vertical axis) as a function of PTA (horizontal axis) will be created, and 
second-order polynomial regression lines will be fit to these figures, which will assist with 
interpreting relationships. Say, for example, the curve has a slightly concave downward shape, 
then clients with very mild hearing loss reported very high mean scores. Logistic regression 
models will also be built. For example, the first question of the RHHI-S instrument asks “Does 
a hearing problem cause you to feel embarrassed when meeting new people?”. Take the first 
question of the RHHI-S, for example. Logistic regression can be utilised to assess predictors 
(age, gender, degree of hearing loss) associated with feeling embarrassed about one’s 
hearing aid when meeting new people. 
The Berman-Syme Social Network Index (SNI) evaluates participants' social connectedness 
based on four domains: (1) marital status, (2) frequency and quantity of contact with friends 
and relatives, (3) participation in religious meetings, and (4) involvement in community or 
organizational groups. Following the approach outlined by Loucks et al. (2006), responses on 
the Berkman-Syme SNI are converted into binary scores and then summed to create a 
composite index ranging from 0 to 4. Participants receive a score of 1 if they are married and 
0 if they are not. For close social contacts, a score of 0 is assigned if an individual reports 
having 0–2 close friends and 0–2 close relatives; otherwise, a score of 1 is given. Regarding 
participation in community organizations, individuals who do not participate receive a score of 
0, while those who do are assigned a score of 1. For religious attendance, a score of 0 is given 
to those attending services less than or equal to every few months, and a score of 1 is 
assigned to those attending once or twice a month or more frequently. The total score reflects 

 
 
 
 
Page 24 of 32 
 
 
the degree of social integration, with higher scores indicating greater social connectedness. 
The scores will be related to the demographic questions (age, gender, degree of hearing loss) 
using correlations and tests for differences. As explained above, the tests for differences 
between two unrelated/independent groups will be conducted using the independent samples 
t-test (if normal) or the Mann-Whitney test (if non-normal). For three or more groups, the one-
way ANOVA test (if parametric) or the Kruskal-Wallis test (if non-normal) will be used. 
Predictors of higher or lower social connectedness scores will be explored using generalized 
linear models, with age, gender and degree of hearing loss included as covariates. 
The EQ-5D-5L is a standardized instrument developed by the EuroQol Group to assess 
health-related quality of life and will serve as one of the secondary outcome measures in this 
trial. It consists of two components: the Descriptive System and the Visual Analogue Scale 
(VAS). The Descriptive System captures participant self-assessment across five domains — 
mobility, self-care, usual activities, pain/discomfort, and anxiety/depression — each rated on 
a five-level scale from "no problems" to "extreme problems." The VAS records the participant’s 
overall health on the day of assessment on a scale from 0 (worst imaginable health) to 100 
(best imaginable health). A utility score will be derived from the five-digit health profile 
generated from the Descriptive System using the most applicable value set. Since no South 
African value set currently exists, this study will use the validated Ugandan value set, which 
has been applied successfully in South African research, including a recent study assessing 
Health-Related Quality of Life among people living with HIV in KwaZulu-Natal (Moyo et al., 
2023). The EQ-5D-5L utility index and VAS scores will be analyzed using both descriptive and 
inferential statistics. Differences between baseline and follow-up scores (at 6, 12, 26, and 52 
weeks) will be assessed using appropriate statistical tests based on data distribution (e.g., 
paired t-tests or Wilcoxon signed-rank tests). Between-group comparisons (in-situ, pre-set, 
and control) will be analyzed using one-way ANOVA (if parametric) or Kruskal-Wallis (if 
nonparametric) tests. Predictors of higher or lower health-related quality of life scores will be 
explored using generalized linear models, with age, gender and degree of hearing loss 
included as covariates. A VAS cut-off score of ≥73 will be used to categorize participants as 
having a good perceived health state, following the threshold used by Moyo et al. (2023). 
Logistic regression models will also be employed to identify factors associated with achieving 
a good health state. These analyses will allow us to assess whether the hearing aid 
interventions lead not only to hearing-specific benefits but also to broader improvements in 
participants’ overall health-related quality of life. 
 
15.1 
Data management 
15.1.1 Data entry and collection 
Data collection will primarily take place in a paper format, which includes the ICF, patient file 
data, as well as the Case Report Form (CRF). Data from the CRF will be electronically 
transcribed for further data analysis.  
 
After obtaining necessary study approvals, the study will employ a comprehensive Subject 
Eligibility Checklist (Appendix XXX) encompassing all inclusion and exclusion criteria. This 
checklist will ascertain an individual's eligibility for study enrollment. Each interested individual 
will undergo this assessment, and the completed form will be securely filed within their 
respective study file. 
 
Each individual who undergoes the screening evaluation, whether eventually enrolled or not, 
will be meticulously documented on the Subject Eligibility Checklist (Appendix XXX) specific to 

 
 
 
 
Page 25 of 32 
 
 
the site. These records will be maintained within the Site Master File (SMF). It is essential to 
emphasize that no procedures to evaluate eligibility will commence without obtaining informed 
consent. Likewise, these records will be securely stored within each individual’s study file. 
 
Personal and demographic data collected for the study will be meticulously recorded on the 
Baseline Data Collection form (Appendix XXX) and kept within the respective participant study 
file. Data from study activities will be accurately documented on the results form (Appendix 
XXX). All study forms will be securely stored in the participant study files.  
 
Each participant will have a dedicated CRF that comprehensively captures and reflects all 
their data. This information will subsequently be transferred to an electronic data system for 
further analysis and management. 
 
15.1.2 Data quality control and validation 
The PI or responsible research team member will maintain all study documents and source 
documentation in their original format in compliance with South African Good Clinical Practice 
(GCP) guidelines.  
To ensure data quality all clinical research audiologists will be trained on the study procedure 
and measures for data collection, prior to participants being assessed. A training log will be 
kept as proof of training and retraining activities. There will be clear data normalization 
protocols, i.e., methods of recording data will be consistently captured on the set data 
collection sheets, and there will be clearly defined protocols for each clinical measure 
conducted throughout the clinical trial. Clinical evaluations will conform to consistent formats 
to ensure consistency in the data. Source data will be captured on fillable forms, and captured 
electronically afterward for statistical analysis.  
Internal monitoring activities will take place to ensure data integrity and completeness. A 
weekly scheduled data validation check will be conducted by the research personnel, where 
data will be reviewed for completeness and accuracy prior to eCRF capturing. Electronically 
transcribed data will also be reviewed for completeness and correctness in relation to the 
source documentation. In addition, the data will be audited for accuracy at each site monitoring 
visit by an independent monitor.  
15.1.3 Data privacy and retention policy 
Following the ICF completion, where identifying information will be visible, an alphanumeric 
code will be assigned to each participant. All data to be collected post-ICF will have the specific 
alphanumeric code to ensure participant anonymity. Only the research personnel working 
directly with the participant will have access to the identifiable information. Data from the CRF 
will be transferred/transcribed to a cloud based electronic data platform (Google Suite) with 2-
factor authentication access in place. 
 
Participant study data will be kept for a minimum of 10 years as set out by the Health Sciences 
Research Ethics Committee of Pretoria.  
  

 
 
 
 
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15.1.4 Data ownership and data sharing 
Data ownership primarily resides with the University of Pretoria and the hearX Foundation who 
oversees the study and retains ultimate ownership of the collected data. However, all parties 
involved, including investigators, institutions, and participants, hold a vested interest and 
responsibility in ensuring data accuracy and integrity. Access to study data, both identifiable 
and unidentifiable, will be strictly limited to authorized personnel. Any sharing or utilization of 
the data (unidentifiable) will necessitate prior approval from the University of Pretoria and the 
hearX Foundation. Distribution, submission, and publication rights shall be vested in HearX 
(Pty) Ltd.  
 
15.1.5 Audit trail 
The study will maintain a comprehensive audit trail to document all entries, changes, additions, 
or deletions made to the study data throughout its lifecycle, whether in paper format or 
electronically transcribed. This audit trail will include, but not be limited to, a record of all data 
entry, modifications, and access logs. Any modifications made to the data will undergo 
rigorous scrutiny. Each alteration will be methodically recorded, and a clear linkage to the 
responsible party for each change will be established. This meticulous audit trail will serve as 
a safeguard against unauthorized data handling and provide transparency in data 
management processes. The maintenance of an audit trail aligns with regulatory 
requirements, ensuring data integrity, traceability, and compliance with GCP guidelines. 
 
Documents need to be retained for at least 15 years since the discontinuation of the clinical 
investigation. Documents may be retained for longer periods of time upon agreement with the 
sponsor or in accordance with regulatory requirements. Records are not allowed to be 
destroyed without written permission from the Sponsor.  
 
16. Adverse events and device defects/deficiencies 
16.1 
Adverse events 
Adverse events (AEs) are any untoward medical occurrence, unintended injury or disease in 
participants related to the investigational device.  
 
For the current clinical investigation, possible AEs could include: 
● Risk of an ear infection due to contamination or cross contamination of disease 
between participants through equipment and/or surface contaminants.  
● Possible allergic reaction from use of the hearing aids, due to device material (e.g. 
itchy ears, or otitis externa). 
● Possible increase in wax build-up due to occlusion of ear canals, which may cause 
itchiness and irritation.  
● Possible headaches from prolonged device use, especially during the first few days of 
use. 
 

 
 
 
 
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16.2 
Serious Adverse Events (SAE) 
Any AE that leads to a death or to a serious deterioration in the health of the participant or that 
resulted in a life-threatening injury, permanent impairment of a body structure/function, 
hospitalization or medical intervention is considered an SAE. For the current clinical 
investigation no SAEs are anticipated.  
 
16.3 
Adverse Device Effect (ADE) 
AE related to the use of an medical device. For the current clinical investigation, possible 
ADEs could include: 
● Device material causing an allergic reaction in a participant’s ear  
● A device deficiency of unintended loud sound output that may result in a temporary 
threshold shift.  
 
16.4 
Device Deficiencies (DD) 
Any device defect related to the identity, quality, durability, reliability, safety or performance of 
the devices. Device deficiencies include malfunctions, use errors, and inadequacy in the 
information supplied by the manufacturer including labeling. For the current clinical 
investigation, a possible DD could include: 
● Any device defect related to the performance or safety of the devices e.g. audio output, 
faulty components that would deviate from the standard performance set out by the 
manufacturer. 
 
16.5 
Adverse event reporting 
All AEs will be recorded on the AE/SAE form and will be added to the participant file.  
The research team will discuss any AE within 48-72 hours of the event occurring and decide 
if any external parities such as the device developers. All AEs will be characterized by the 
following criteria as set out in Table 3. 
 
 
Table 3. Adverse Event criteria 
Criteria  
Grading 
Severity  
Mild 
Moderate 
Marked  
Severe 
Relationship  
Not related 

 
 
 
 
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Definitely related  
Action taken 
None 
Study intervention modified 
Study intervention discontinued  
Subject withdrawal from study 
Hospitalisation 
Other 
Outcome  
Resolved  
Ongoing 
Worsening 
Death 
Unknown  
Expected  
Yes 
No 
 
17. 
Amendments and deviations to the protocol 
A protocol deviation is described as an event where the investigator, research team member 
or the site personnel did not conduct the study in accordance with the investigational protocol 
or agreement.  
 
The clinical trial will be conducted in compliance with the SA GCP guidelines along with the 
applicable regulatory requirements. The sponsor should notify the regulatory authority and EC 
of any changes in the study protocol/documentation. If the sponsor intends to make changes 
after approval has been obtained, a re-application should be submitted to the relevant 
authority and EC, indicating the contents and grounds for change. Essential changes are such 
changes that can have an effect on the safety of the participants, influence interpretation of 
results or influence requirements assessed by the ECs.  

 
 
 
 
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Investigators, research team members or site personnel need to obtain approval from the 
clinical study management team before deviating from the investigational protocol, except in 
an instance where it is necessary to protect the life or physical well-being of a participant in 
an emergency. All approvals need to be documented in writing and maintained in the study 
files. Prior approval is not expected in situations where there are unforeseen circumstances 
which are beyond the control of the investigator, research team, or site personnel.  
 
17.1 
Protocol deviations & study violations 
Protocol Deviation: An accidental or unintentional change to, or non-compliance with the 
research protocol that does not increase risk or decrease benefit or does not have a significant 
effect on the participants, safety or well-being; and/or the reliability of the study data. 
Examples of possible protocol deviations may include:  
● Inadequate record keeping: Incorrect and missing data captured during study 
assessments/evaluations.  
● Incorrect participant enrollment: Enrolling a participant who did not meet the stipulated 
inclusion/exclusion criteria. 
Study Violation: A change, divergence from the study design or procedures defined in the 
protocol that might significantly affect participants’ safety, and well-being and/or the reliability 
of the study data.  
Examples of possible study violations may include:  
● Incorrect or missing study procedures: Conducting/ performing new procedures/ 
assessments/ evaluations not in line with the original approved clinical investigational 
protocol.   
● Unreported AE/SAEs: Not reporting or documenting AE/SAEs that occur during the 
clinical investigational study, that can affect the safety of the study participants.  
Reporting Requirements: 
PIs/site coordinators and their teams must report (Appendix XXX) to the study sponsor and 
any protocol deviations. This should in turn be documented and submitted to the EC for review. 
Study violations should be reported within 24 hours of the event.  
Documentation and Storage: 
All deviation reports and related documents will be kept in the SMF and digital copies of it will 
be stored electronically on a cloud-based Google server with 2-factor authentication and strict 
access control.  
Reporting: 
Protocol deviations will also be documented in the final study report upon study conclusion.  
Personnel Training: 

 
 
 
 
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Study personnel will receive pre-study communication training regarding deviation definitions 
and reporting timeframes to ensure accurate reporting. Training records will be kept for all 
personnel. 
 
18. Dissemination Plan 
The study team is committed to disseminating results to contribute to the body of evidence in 
hearing healthcare delivery in low- and middle-income communities. All dissemination will 
comply with NIH Policy on the Dissemination of Clinical Trial Information. The trial will be 
registered on ClinicalTrials.gov no later than 21 calendar days after the study start date. Once 
registered, the study team will: 
 
• 
Verify the accuracy of record content and resolve any discrepancies.  
• 
Maintain and update records at least annually, or more frequently as required by NIH 
and ClinicalTrials.gov regulations.  
• 
Submit aggregate adverse event data at the conclusion of the trial. 
• 
Submit the primary results to ClinicalTrials.gov within 12 months of the study 
completion date (see study timeline). 
 
The University of Pretoria and hearX Foundation have established internal procedures to 
ensure compliance with NIH and ClinicalTrials.gov requirements for registration and results 
reporting. 
 
Dissemination of Results to Community Partners 
The hearX Foundation and collaborating CHWs have established community engagement 
protocols to ensure that study findings are shared back with participating communities in a 
culturally and linguistically appropriate manner. This will include: 
 
• 
Co-developing a one-page lay summary of results (in English, isiXhosa, and Sepedi) 
and an accompanying PowerPoint presentation with input from CHWs and community 
advisory boards. 
• 
Sharing findings at community meetings, with local leadership bodies, elderly clubs, 
and NGOs. 
 
Dissemination to the Scientific and Professional Community 

 
 
 
 
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Results will be presented at national and international conferences in audiology, rehabilitation, 
and public health. The team will also seek opportunities to present at interdisciplinary 
conferences focused on digital health, community health worker programs, and LMIC health 
innovation. 
 
Peer-Reviewed Publications  
Study findings will be submitted to high-impact, peer-reviewed journals in audiology, 
rehabilitation, and global health.  
 
19. 
References 
 
1. Aazh, H., Deepak, P., Kiran, N., & and Moore, B. C. J. (2015). Hearing-aid use and its 
determinants in the UK National Health Service: A cross-sectional study at the Royal 
Surrey County Hospital. International Journal of Audiology, 54(3), 152-161. 
https://doi.org/10.3109/14992027.2014.967367  
2. American National Standard- Specifications for Audiometers (ANSI/ASA S3.6-2018). 
3. ANSI S3.6-2010 : Specifications for Audiometers. 
4. Arlinger, S., Nordqvist, P., & Öberg, M. (2017). International Outcome Inventory for 
Hearing Aids: Data From a Large Swedish Quality Register Database. Am J Audiol, 
26(3s), 443-450. https://doi.org/10.1044/2017_aja-16-0123  
5. Baicus, C., &amp; Caraiola, S. (2009). Effect measure for quantitative endpoints: 
Statistical versus clinical significance, or “how large the scale is?”. European Journal 
of Internal Medicine, 20(5), e124-e125. https://doi.org/10.1016/j.ejim.2008.10.002 
6. Bisgaard, N., Zimmer, S., Laureyns, M., & Groth, J. (2021). A model for estimating 
hearing aid coverage world-wide using historical data on hearing aid sales. 
International 
Journal 
of 
Audiology, 
1-9. 
https://doi.org/10.1080/14992027.2021.1962551  
7. Cohen, J. (1969). Statistical power analysis for the behavioral sciences. Academic 
Press. 
8. Cox RM, Rivera I. Predictability and reliability of hearing aid benefit measured using 
the PHAB. J Am Acad Audiol. 1992;3(4):242-54. 
9. Cox RM, Alexander GC. The International Outcome Inventory for Hearing Aids (IOI-
HA): psychometric properties of the English version: El Inventario International de 
Resultados para Auxiliares Auditivos (IOI-HA): propiedades psicometricas de la 
version en ingles. International journal of audiology. 2002;41(1):30-5. 
10. Department of Health, 2020. South African Good Clinical Practice: Clinical Trial 
Guidelines Pretoria, South Africa (third edition). https://www.sahpra.org.za/wp-
content/uploads/2021/06/SA-GCP-2020_Final.pdf 
11. Field, A. P. (2024). Discovering statistics using IBM SPSS statistics (6th edition ed.). 
SAGE.  
12. Herdman, M., Gudex, C., Lloyd, A., Janssen, M. F., Kind, P., Parkin, D., Bonsel, G., & 
Badia, X. (2011). Development and preliminary testing of the new five-level version of 

 
 
 
 
Page 32 of 32 
 
 
EQ-5D 
(EQ-5D-5L). 
Quality 
of 
Life 
Research, 
20(10), 
1727-1736. 
https://doi.org/10.1007/s11136-011-9903-x  
13. ISO 8253-1:2010(en) Acoustics — Audiometric test methods — Part 1: Pure-tone air 
and bone conduction audiometry. 
14. Keidser G, Dillon H, Flax M, Ching T, Brewer S. The NAL-NL2 prescription procedure. 
Audiology research. 2011;1(1):88-90. 
15. Loucks, E. B., Sullivan, L. M., D'Agostino, R. B., Sr., Larson, M. G., Berkman, L. F., & 
Benjamin, E. J. (2006). Social networks and inflammatory markers in the Framingham 
Heart 
Study. 
J 
Biosoc 
Sci, 
38(6), 
835-842. 
https://doi.org/10.1017/s0021932005001203  
16. Mccabe, D. (2019). Hearing Screening in Older Adults. Best Practices in Nursing Care 
to 
Older 
Adults(12). 
https://hign.org/sites/default/files/2020-
06/Try_This_General_Assessment_12.pdf  
17. Mulwafu, W., Ensink, R., Kuper, H., & Fagan, J. (2017). Survey of ENT services in Sub 
Saharan Africa: Little Progress Between 2009 and 2015. Global Health Action, 10(1), 
1289736–1289736. https://doi.org/1289710.1281080/16549716.16542017.11289736.  
18. Peeters, M. J. (2016). Practical significance: Moving beyond statistical significance. 
Currents in 
19. Stephens, D. (2002). The International Outcome Inventory for Hearing Aids (IOI-HA) 
and its relationship to the Client-oriented Scale of Improvement (COSI). Int J Audiol, 
41(1), 42-47. https://doi.org/10.3109/14992020209101311  
20. World Health Organization. (2021). World Report on Hearing. Available from: 
https://www.who.int/publications/i/item/world-report-on-hearing 
21. World Health Organization. (2024). Hearing aid service delivery approaches for low-
and middle-income settings. World Health Organization.