Using Headphone Presentation to Investigate Compression Strategy Modifications in Hearing Aids for Moderate-to-severe Hearing Loss
Phase: NA
Conditions: Hearing Loss
Sponsor: Sonova AG

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Study Protocol and Statistical Analysis Plan 
 
Using Headphone Presentation to Investigate Compression Strategy 
Modifications in Hearing Aids for Moderate-to-severe Hearing Loss   – 
ID# 365 
 
August 3rd, 2021 
 
NCT04882709  
 

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Using Headphone Presentation to Investigate Compression Strategy 
Modifications in Hearing Aids for Moderate-to-severe Hearing Loss   – 
ID# 365 
 
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 insight on general and individual preferences of fast and slow compression time constants 
generated in this study will be used to propose compression parameters for new hearing aids, 
which will be investigated in an in-person follow-up study.  
1.2 Primary and Secondary Objectives  
The primary objective of this study is to identify the most preferred compression setting for 
various acoustic scenes in experienced hearing aid users with moderate-to-severe hearing loss 
by subjectively rate recorded stimuli presented through headphones. 
The secondary objective is to investigate potential benefit of a modifier for these compression 
settings by analyzing trends in individual preferences and their potential dependencies, such as 
hearing loss, acoustic scenes and previous amplification strategies. 
2 Design of the clinical investigation 
2.1 General 
2.1.1 Design Type 
This is a randomized, double-blinded, cross-over, remote study with participants serving as self-
controls and the current default compression setting as well as a competitor’s hearing aid as 
comparator. An unaided recording will be provided as reference. 
2.2 Procedures 
2.2.1 Investigation-related Procedure  
The study is conducted remotely, so a potential participant’s eligibility will be determined based 
on audiograms on file. If the study site doesn’t have a participant’s audiogram on file, the 
potential participant can request their HCP to release an audiogram to a study site.  
After successful completion of the screening call, participants will sign the consent form and 
complete the demographic questionnaire over the phone. Afterwards, they will receive a 
package with a tablet and headphones and will get on another call with the researcher to 
conduct the subjective rating via an online sound survey tool.  
The subjective rating will include rating of reverberation, sound source separation, sound source 
localization, overall preference ranking and an A/B test for preference. The stimuli consist of 
speech in quiet, speech in noise, reverberant speech, and music recorded with different hearing 
aids and hearing aid settings (hearing aids set to fast and slow compression settings, default 

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compression setting, a competitor’s hearing aid and unaided), post-processed for headphone 
presentation and incorporated in an online sound survey.  
3 Statistical design and analysis 
3.1 Determination of Sample Size 
We will recruit up to 28 participants, including up to 6 pilot participants. Previous research with 
subjective ratings has repeatedly shown that data collected with 15-25 participants can yield 
significant results. Since participants do not need to visit the research site, participants will be 
recruited from both locations as available. 
Statistical criteria of termination of trial 
If results for sound quality ratings are significant after 15 participants completed the rating, we 
will consider terminating the data collection. 
3.2 Planned Analyses 
3.2.1 Datasets to be analyzed, analysis population 
• 
Analysis population: 15-25 participants 
• 
Evaluation group: rating per setting 
• 
Data sets: subjective ratings 
• 
Additional analyses:  
o individual preferences and their potential dependencies, such as hearing loss, 
acoustic scenes and previous amplification strategies 
o correction for repeated measures. 
3.2.2 Primary Endpoint Analysis 
Automatic data analysis is available in the survey tool and will be used throughout the data 
collection for interim analysis. The study manager will analyze the collected data set in R 
Statistics after the data collection completed. Microsoft Excel may be used for arranging data 
and plotting data sets. 
3.2.3 Secondary Endpoint Analysis 
The study manager will analyze the collected data set in R Statistics after the data collection 
completed. 
Subgroup analyses: 
• 
Hearing loss: H0: There is no significant difference in sound quality ratings among all 
tested conditions depending on hearing loss degree. 
• 
Acoustic scenes: H0: There is no significant difference in sound quality ratings among all 
tested conditions depending on acoustic scene. 
• 
Previous amplification strategies: H0: There is no significant difference in sound quality 
ratings among all tested conditions depending on previous amplification strategy of 
participants. 

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. 
3.2.4 Interim Analysis 
Automatic data analysis is available in the survey tool and will be used throughout the data 
collection for interim analysis. Data will be adjusted for repeated measures.  
3.3 Handling of missing data and drop-outs 
Drop-outs will be replaced if possible (depending on participant availability and schedule). 
Smaller data sets will be analyzed if the data is complete for sub-sets of the investigation.