A methodical evaluation of new CE-labelled Phonak Hearing Systems is intended to be conducted on hard of participants with a hearing loss to grant quality control prior to product launch. The aim of the investigation series is to ensure a stable overall performance of the new hearing systems, a good sound quality during phone calls as well as maximum benefit for the participant with the devices.

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 in the way as planned for this study ("phase of final inspection"). This will be a clinical evaluation which will be conducted mono centric at Sonova AG Headquarters based in Stäfa (Switzerland).

Inclusion Criteria:

• Adult hearing impaired persons (minimum age: 18 years) with and without (experience with) hearing aids
• Good written and spoken (Swiss) German language skills
• Healthy outer ear
• Ability to fill in a questionnaire (p/eCRF) conscientiously
• Informed Consent as documented by signature
• Smartphone user

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
• Massively limited dexterity
• Known psychological problems
• Central hearing disorders