Participants will complete a listening task in a simulated reverberant environment. Participants are seated and instructed to look at a fixation cross while a sentence is played. Sentences are varied with respect to their speech rate. While listening to the sentences participant's pupil dilation is measured by means of pupillometry which is a non-invasive physiological measurement. Participants are asked to repeat back the sentences loud. At fixed intervals, subjective ratings are collected by asking participants to move an on-screen slider using a game controller. Two hearing aid programs will be compared, one intended for speech perception in quiet and the other to reduce reverberation in reverberant environments. The study is designed as factorial, with 2 speech rates, 2 room simulations and 2 hearing aid programs. The same conditions will be re-tested once after a minimum of one day. A pilot study will determine appropriate speech rates by applying a different factorial, with 4 speech rates, 2 room simulations and 1 hearing aid program. Participants complete all conditions (within-subjects) in one experimental sessions that lasts around 1 hour.

Inclusion Criteria:

• Healthy outer ear (without previous surgical procedures)
• Ability to fill in a questionnaire conscientiously
• Informed Consent as documented by signature
• Mild-Moderate/Severe (N2-N4) hearing loss

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
• 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
• Known central hearing disorders