Quality Control of CE-Certified Phonak Hearing Aids - 2020_43

Study Overview
=================
Brief Summary
-----------------
Phonak Hearing Systems pass through different development and study stages. At an early stage, feasibility studies are conducted to investigate new algorithms, features and functions in an isolated manner. If the benefit is proven, their performance is then investigated regarding interdependency between all available algorithms, features and functions running in parallel in a hearing aid (pivotal/pre-validation studies) and, as a result, they get optimized. Afterwards, and prior to product launch, the Phonak Hearing Systems undergo a final quality control in terms of clinical trials. This is a pre-validation study, investigating optimized algorithms, features, functions and wearing comfort. This will be a clinical investigation which will be conducted mono centric at Sonova AG Headquarters based in Stäfa (Switzerland).

Detailed Description
-----------------
The study will compare different features of the Phonak behind the ear device activated and deactivated, for example the noise reduction feature. There shall be differences in listening effort, awareness and sound quality shown. The study shall show the advantages especially for people with severe to profound hearing losses. This will be a clinical investigation which will be conducted mono centric at Sonova AG Headquarters based in Stäfa (Switzerland).

Official Title
-----------------
Quality Control of CE-Certified Phonak Hearing Aids - 2020_43

Conditions
-----------------
Hearing Loss

Intervention / Treatment
-----------------
* Device: Feature for noise reduction (on)
* Device: Feature for noise reduction (off)


Participation Criteria
=================
Eligibility Criteria
-----------------
Inclusion Criteria: Adult hearing impaired persons (minimum age: 18 years, severe to profound Hearing loss) Good written and spoken (Swiss) German language skills Healthy outer ear Ability to fill in a questionnaire (p/eCRF) conscientiously willingness to wear Behind-the-ear hearing aids Informed Consent as documented by signature Exclusion Criteria: Contraindications to the MD in this study, e.g. known hypersensitivity or allergy to the investigational product Limited mobility and not in the position to attend weekly appointments in Stäfa (Switzerland) Limited ability to describe listening impressions/experiences and the use of the hearing aid Inability to produce a reliable hearing test result Known psychological problems

Ages Eligible for Study
-----------------
Minimum Age: 18 Years
Maximum Age: 99 Years

Sexes Eligible for Study
-----------------
All

Accepts Healthy Volunteers
-----------------
No

Study Plan
=================
How is the study designed?
-----------------

Design Details

Primary Purpose: Other
Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Experimental device: Noise reduction on<br>The noise reduction is activated. The feature shall support the hearing aid user in noisy situation and shall reduce the listening effort in these special situations. | Device: Feature for noise reduction (on)<br>* The noise reduction feature shall support the hearing aid user in noisy situations and shall reduce the listening effort.<br>|
| Active Comparator: Experimental device: Noise reduction off<br>To compare the advantage of the special noise reduction feature the tests will be done additionally with the deactivated feature. | Device: Feature for noise reduction (off)<br>* To show the advantage of the noise reduction feature there is a comparison without the feature necessary.<br>|

What is the study measuring?
-----------------
Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Subjective Listening Effort Scaling | A listening effort scaling procedure ('ACALES'; Krueger et al, 2017) was performed with noise cancellation on and off. ACALES is adaptive, altering the signal-to-noise ratio (SNR) at which speech is presented. Therefore it is not a simple rating scale. For each stimulus, a rating (14-point scale ranging from 1='effortless' to 14= 'only noise') was given for how effortful it was following speech. This results in 2-D data: a list of presentation SNRs (different for each participant), and respective participant ratings. Given the format of this data, it cannot be summarized using standard descriptive statistics. We defined SNR as the dependent variable and fitted a linear mixed effects model, with the predictors: listening effort rating & intervention (treating participants as a random factor), characterizing SNR over the entire rating scale. The values reported represent the estimated marginal means of SNR for each intervention, averaged across effort ratings & participants. | 2 weeks | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Subjective Ratings of Speech and Music Samples (Part1: Sound Quality) | The secondary Outcome measure of this study contains 2 parts. This first part reported here was the evaluation of the sound quality. A comparison was made between speech and music audio excerpts either with or without gain being increased by the feedback manager. Subjective ratings of sound quality were made under both of these conditions for one speech and one music sample, using the following scale: Bad (1) - Poor (2) - Fair (3) - Good (4) - Excellent (5). Results were analyzed separately for the speech and music samples. | 4 weeks | 
| Measure of Detection Threshold (in dB) for Soft Sounds | This outcome measure evaluated the ability to detect sounds in a quiet environment. A comparison was made between the feature under investigation being activated and deactivated. Participants were asked to change the level of a speech sample until they were just able to detect it. The ability will be measured by a detection threshold (in dB). | 2 weeks | 
| Subjective Ratings of Speech and Music Samples (Part 2: Artefact Perception) | The second part of this secondary Outcome measure was the evaluation of audible artefacts either with or without the available gain being increased by the feedback manager. The outcome was measured as a binary response (artefacts audible/ not audible). Participants had to indicate whether artefacts were audible under both of these conditions. The number of positive ratings (artefacts were audible) was counted. | 2 week |