Lab Evaluation of Novel Hearing Aid Coupling Method
Phase: NA
Conditions: Hearing Loss
Sponsor: Sonova AG

 
 
 
 
 
 
 
Study Protocol and Statistical Analysis Plan 
 
Lab Evaluation of Novel Hearing Aid Coupling Method - ID# 1082 
January 30, 2024 
 
NCT05377359 
 
 
 
 
 
 
 
 
 
 
 
 
 
 

Lab Evaluation of Novel Hearing Aid Coupling Method - ID# 1082 
1 Objectives and hypotheses of the clinical investigation 
1.1 Purpose of the clinical investigation claims for clinical performance, 
effectiveness or safety of the investigational device that are to be verified 
The study was an exploratory study in which we evaluated a novel coupling method that allows us to take 
advantage of both open and closed fittings in a single solution and compared this to traditional coupling 
methods. The various coupling methods were evaluated using two outcome measures: streaming sound 
quality and situational preference.   
1.2 Primary Objective  
The primary objective of this study was to determine if participants with mild to moderately-severe SNHLs 
find an improvement in streaming sound quality under the novel coupling method (state 1) when 
compared to the novel coupling method (state 2). Additionally, streaming sound quality of the novel 
coupling method was compared to traditional open and vented domes.  
1.3 Secondary Objectives 
The secondary objective of this study was to determine how overall preference ratings for streamed 
stimuli in realistic noise changes when using novel coupling methods while in different states and while 
the hearing aid mic is on and off. 
2 Design of the clinical investigation 
2.1 General 
2.1.1 Design Type 
This study was a single-blinded, single group interventional study where stimulus presentation order was 
randomized between participants. All participants were subject to each test condition (cross-over). There 
was no control group. Participants and investigators were always blinded to the programs that were being 
rated during testing. 
The table below indicates the various programs that each participant evaluated. 
Primary 
Objective 
Novel Coupling Method – State 1 
Novel Coupling Method – State 2 
Open Domes 
Vented Domes 
Secondary 
Objective 
Novel Coupling Method – State 1 – Mic Off 
Novel Coupling Method – State 1 – Mic On 
Novel Coupling Method – State 2 – Mic Off 
Novel Coupling Method – State 2 – Mic On 
 
 

2.2 Procedures 
2.2.1 Investigation-related Procedure  
Recruitment paths: 
• 
Western University’s internal database was accessed to see if any potential participants who fit 
the inclusion criteria were available. 
• 
Referrals from hearing healthcare providers in the London and surrounding area were requested.  
• 
Self-referral from clinical investigation postings. 
 
Tasks: 
Appointment tasks are listed in the table below. 
Tasks per appointment visit. 
Visit 1 
Visit 2 
• 
The visit would last approximately 2 hours. 
• 
Participants were asked to complete the 
following: 
o Review and sign study consent form and 
related forms 
o Hearing test was completed (including 
otoscopy, tympanometry, speech testing 
(SRT and WRS), and pure-tone threshold 
testing (air and bone)) 
• 
The visit would last approximately 2 hours. 
• 
Participants were asked to complete the 
following: 
o Streaming sound quality task (primary 
objective)  
o Situational 
preference 
task 
(secondary 
objective) 
2.3 Determination of Sample Size 
Sample size was estimated based on a previous version of the study in which the primary outcome was 
speech in noise recognition. Sample size was estimated using GPower software, for repeated measures 
ANOVA (Faul et al., 2007; Faul et al., 2009). Past studies in this area have typically used about 20 
participants. It should be noted that as a post-market exploration study, a formal sample size estimation 
for the sound quality evaluation is not mandatory.  
2.4 Statistical criteria of termination of trial 
n/a 
2.5 Planned Analyses 
2.5.1 Datasets to be analyzed, analysis population 
Datasets to be analyzed:  
• 
Demographic information (e.g., hearing profiles, hearing aid experience, age, etc.) will be analyzed. 
• 
Sound Quality: Subjective ratings (fullness, sharpness, overall preference) (1-100) 
• 
Situational Preference: Subjective ratings (overall preference) (1-100) 
2.5.2 Primary Endpoint Analysis 
Sound quality ratings were analyzed using ratings on a scale from 1-100. Ratings were transformed to 
rationalized arcsine units (Studebaker, 1985). Transformed scores were inspected for normality by visual 
inspection of histogram data, and protected against departures from sphericity using Greenhouse-Geisser 
corrections to degrees of freedom. Scores were analyzed using a 3x4 repeated measures analysis of 

variance (RM-ANOVA) with stimulus (classical, pop, speech) and condition (state 1, state 2, open dome, 
closed dome) as the within-subjects factors. Significant effects were located using pairwise comparisons 
with Bonferroni corrections.  
2.5.3 Secondary Endpoint Analysis 
Situational preference data were analyzed using a 2x2x2 RM-ANOVA with condition (state 1, state 2), 
microphone state (on vs. off), and stimulus (music, speech) as within-subjects factors. Data and analysis 
followed the same treatment procedures as for the sound quality data. A separate RM-ANOVA was run 
for when participants were focusing on the stream and for focusing on the external environment. Planned 
contrasts included: comparison of conditions and or microphone states across stimuli, and comparison of 
conditions and or microphone states within each stimulus. Comparisons between stimuli were not of 
interest. 
2.5.4 Interim Analysis 
N/A 
3 Informed consent process 
3.1 Process for obtaining informed consent.  
Participants are presented with the Letter of Information (LOI) by email, mail, or in person. They are 
provided time to review the LOI. They are permitted to ask any questions they have about the information 
in the LOI. They will then sign the letter of information. A member of the study staff will also sign the LOI. 
A copy of the LOI is provided to the participant. 
Faul, F., Erdfelder, E., Lang, A.-G., & Buchner, A. (2007). G*Power 3: A flexible statistical power analysis 
program for the social, behavioral, and biomedical sciences. Behavior Research Methods, 39, 175-
191. 
Faul, F., Erdfelder, E., Buchner, A., & Lang, A.-G. (2009). Statistical power analyses using G*Power 3.1: 
Tests for correlation and regression analyses. Behavior Research Methods, 41, 1149-1160. 
Studebaker, G. A. (1985). A “rationalized” arcsin transform. Journal of Speech and Hearing 
Research, 28, 455-462.