The aim of this study is to compare the audiological and quality of life performance patients have with an ADHEAR (adhesive bone conduction device) compared to no hearing device.

Patients will be recruited at the outpatient's department of the Medical University of Vienna - Otorhinolaryngology department. Patient will be asked to participate in the study when inclusion and exclusion criteria are met. Mostly patients scheduled for a surgery improving conductive hearing loss or scheduled for implantation of an implantable bone conduction hearing aid will be included in the study.

Patients who do not use a hearing aid and who are not planning on using a hearing aid meeting the inclusion and exclusion criteria will also be asked to participate in the study. After inclusion in the study patients will be asked to fill out two questionnaires (quality of life and hearing specific questionnaire). They will then be fitted with an ADHEAR device and undergo unaided and aided soundfield audiometry. Randomization will be carried out (Randomization ratio 1.4:1) and patients in the intervention group will keep the device for the following 4 months with one visit after the first probation time of one month. At the one month mark patients in the control group will be asked to fill out the two questionnaires. Patients in the control group will be asked to return to the department and fill out the three questionnaires (SSQ-12 (Speech Spatial and Hearing Questionnaire), AQoL(Assessment of Quality of Life) and In-house questionnaire). Further audiologic assessment will be carried out. At this appointment patients will be able to talk about their experiences in the probation period und easily terminate the study in case of insufficient improvement, pain, skin irritations or other issues. At the four month mark patients in both groups will be asked to return for audiologic assessment and for filling out the questionnaires.

Inclusion Criteria:

• Unilateral and/or bilateral conductive hearing loss (CHL)
• Conductive hearing loss >10 decibel on average
• Subjective benefit from the device
• Subjects aged 13 years or older
• Capable of the German language
• Willingness and ability to perform all tests required for the study
• Signed, and dated informed consent before the start of any study specific procedure

Exclusion Criteria:

• Pregnancy or breastfeeding
• Patient uses a hearing aid or plans to acquire a hearing aid
• Patient is intolerant of the materials as described by Manufacturer
• Patient presents with a skin or scalp condition that may preclude the attachment of the adhesive adapter.
• Patient cannot perform the audiological tests or is unable to fill out the questionnaires.
• Patient presents with retrocochlear, or central auditory disorder.
• any physical, psychological, or emotional disorder that would interfere with the ability to perform on test and rehabilitation procedures