A methodical evaluation of novel measurement and fitting methods for individualizing CE-labelled Sonova brand hearing instruments (e.g. Phonak hearing instruments) is intended to be conducted on hearing impaired participants. The aim of the study is to investigate and asses strength and weaknesses of these novel measurement and fitting methods in terms of optimizing hearing performance and experience and/or usability of the hearing aids and accessories. Both laboratory measurements as well as evaluations in real life environments will be carried out. This will be a controlled and randomised active comparator clinical evaluation which will be conducted mono-centric at Sonova AG Headquarter based in Stäfa.

Participants fulfilling all of the following inclusion criteria are eligible for the study:

• Adult hearing impaired persons (minimum age: 18 years) with and without (experience with) hearing aids
• Healthy outer ear (without previous surgical procedures)
• Ability to fill in a questionnaire (p/eCRF) conscientiously
• Informed Consent as documented by signature

The presence of any one of the following exclusion criteria will lead to exclusion of the participant:

• 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 appointments
• Limited ability to describe listening impressions or to use hearing aids/ accessories
• Inability to produce a reliable hearing test result
• Massively limited dexterity
• Known psychological problems
• Known central hearing disorders