Inclusion Criteria:  Adult subjects, 18 years or older. Subjects with conductive or mixed hearing loss. Subjects with historically documented diagnosis of Chronic Otitis Media (COM) with or without cholesteatoma in the operated ear. Subjects who have undergone primary tympanoplasty type I-V to improve hearing between 2010-2015. Subjects with an air-bone gap ≥30 decibels (dB) within 3 months after primary tympanoplasty in the operated ear. For Spain only: Subjects with an air-bone gap ≥30 decibels (dB) within 6 months after primary tympanoplasty in the operated ear. Subjects who have tried a hearing aid to improve hearing in the operated ear. Pre-op audiogram, maximum 1 year prior to the primary tympanoplasty, and post-op audiogram for the primary tympanoplasty are available. Available aided audiogram, unaided if no hearing device is used, not older than one year at the point of enrolment. Subjects are fluent in the language used for study questionnaires: German, French, Spanish. Subjects are willing and able to provide written informed consent. For France: subjects do not oppose to participate in the study. Medical Record data is available throughout the defined data search period, from primary tympanoplasty to point of enrolment.  Exclusion Criteria:  Subjects are unable or unwilling to comply with the requirements of the study as determined by the investigator. Investigator site personnel directly affiliated with this study and/or their immediate families; immediate family is defined as a spouse, parent, child, or sibling. Cochlear employees or employees of Contract Research Organizations or contractors engaged by Cochlear for the purposes of this study.  For France only:  Subjects who are not affiliated to social security. Subjects who are under legal protection.