Effect of Speech Enhancer on Listening Effort With EEG

Inclusion Criteria: * Experienced (minimum use duration 6 months) * Adult (minimum age: 18 years) hearing aid users, * Symmetrical hearing loss (difference between ears \<= 10 dB for 1kHz-6kHz), * Sensorineural hearing loss, * Air Conduction - bone conduction gap \<= 10 dB, * Written and spoken German, * Ability to understand instruction, * Ability to describe listening experiences, * Ability to attend to the appointments, * Healthy outer ear (without previous surgical proce-dures), * Hearing loss within the fitting ranges of the investiga-tional product, * Informed consent as documented by signature. Exclusion Criteria: * Clinical contraindications deformity of the ear (closed ear canal or absence of pinna), * Known hypersensitivity or allergy, * Not willing to wear the hearing aid, * Fluctuating hearing that could influence the results, * Limited mobility and not in the position to attend all appointments, * Inability to produce a reliable hearing test result, * Massively limited dexterity, * Known psychological problems, * Known central hearing disorders.