Assessment of Novel Sound Changing Principles in Hearing Instruments to Determine Their Application - 2020_09

Study Overview
=================
Brief Summary
-----------------
Participants will perform two different listening tasks: (1) listening to, and repeating back, sentence lists presented in noise, and (2) Subjective rating of effort & performance following each condition. During this study, continuous, non-invasive physiological measurements (skin conductance, changes in pupil dilation) will be recorded from participants. Using this paradigm we will be assessing the effect of different hearing aid processing algorithms on listening effort. The study takes the form of a one factor (algorithm), within-subjects design. Each participant performs the Speech perception task with each algorithm (reference, noise reduction I, noise reduction II, noise reduction III), at two individualized signal-to-noise ratios (SRT90 and SRT50). Additionally subjective performance ratings in real-life will be collected.

Official Title
-----------------
Assessment of Novel Sound Changing Principles in Hearing Instruments to Determine Their Application - 2020_09

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

Intervention / Treatment
-----------------
* Device: Hearing Aid without NR enabled
* Device: Hearing Aid with NR(1)
* Device: Hearing Aid with NR(2)
* Device: Hearing Aid with NR(3)


Participation Criteria
=================
Eligibility Criteria
-----------------
Inclusion Criteria: Healthy outer ear (without previous surgical procedures) Ability to fill in a questionnaire conscientiously Informed Consent as documented by signature Minimum 1 year hearing aid experience Moderate-Severe (N3-N5) hearing loss or Normal Hearing 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 Inability to produce a reliable hearing test result Massively limited dexterity Known psychological problems Known central hearing disorders

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: Treatment
Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: Hearing Aid without NR(0) enabled<br>Hearing Aid without Noise Reduction (NR 0) enabled serves as reference condition. | Device: Hearing Aid without NR enabled<br>* Each participant will be fitted with noise reduction disabled. Disabled means that no sound processing algorithm that removes noise from the speech signal is active.<br>|
| Experimental: Hearing Aid with NR (1)<br>Hearing Aid with Noise Reduction I (NR) enabled. | Device: Hearing Aid with NR(1)<br>* Each participant will be fitted with the noise reduction program on the same hearing aid. The principle of the noise reduction algorithm is to remove noise from a speech signal with the aim of improving the speech intelligibility and comfort.<br>|
| Experimental: Hearing Aid with NR(2)<br>Hearing Aid with Noise Reduction II (NR) enabled. | Device: Hearing Aid with NR(2)<br>* Each participant will be fitted with a second noise reduction program on the same hearing aid. The parameterization of this NR algorithm differs from that in NR(1).<br>|
| Experimental: Hearing Aid with NR(3)<br>Hearing Aid with Noise Reduction III (NR) enabled. | Device: Hearing Aid with NR(3)<br>* Each participant will be fitted with a third noise reduction program on the same hearing aid. The parameterization of this NR algorithm differs from that in NR(1) and NR(2).<br>|

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

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Differences in Event-related-skin-conductance | Skin conductance will be recorded from participants during the performance of the auditory task. Analyses will be carried out on the skin conductance response recorded during a time window following each auditory stimulus. It is planned to analyze event-related skin conductance response amplitudes & latencies (micro-Siemens & milliseconds). | 6 weeks | 
| Differences in Event-related-pupil-dilation (ERPDs) | Pupil dilations will be recorded from the participant during the performance of the auditory tasks. Analyses will be carried out relative to the pre-trial baseline (measured one second prior to the onset of the stimulus), in order to account for differences in baseline physiological activity. It is planned to analyze event-related-pupil-dilations. We use the unit: pixels. The size of a pixel in 1mm^2 is relative to the distance between the eye and the camera. Even though participants heads were placed on a chin rest that was always the same distance from the camera, the distance between the individual eye and the camera can still be different due to differences in participants' anatomies. Thus, pupil dilation are often reported relative to an individuals' baseline, for example as percent change relative to the baseline. Therefore, we use the unit: pixels, as the use of mm^2 may be inaccurate. | 6 weeks | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Oldenburg Sentence Test | Words recalled correctly: words repeated back by participants are logged and the percentage of words recalled correctly calculated. | 6 weeks | 
| Sound Quality Ratings | The sound quality ratings will be assessed with the aid of a Multi-Stimulus Test. The data, serving as secondary outcome measure, are collected in the laboratory. The scale ranges from 0 very bad to 6 very good in increments of 1. Individual sound quality rating from participants are averaged over 3 different acoustic scenes for each hearing aid program. | 6 weeks | 
| Spectro-temporal-modulation Detection Thresholds (STM) | Stimuli which contain simultaneous frequency and amplitude modulations of a wide-band noise carrier are presented to the participants. The depth of the modulations is systematically varied and the individual modulation detection thresholds are recorded as a broadband decibel (dB) value. For each participant 4 measures were made and averaged to give a mean STM threshold. | 6 weeks |