Mice, Inbred Strains: Genetically identical individuals developed from brother and sister matings which have been carried out for twenty or more generations, or by parent x offspring matings carried out with certain restrictions. All animals within an inbred strain trace back to a common ancestor in the twentieth generation.Hearing Loss: A general term for the complete or partial loss of the ability to hear from one or both ears.Cochlea: The part of the inner ear (LABYRINTH) that is concerned with hearing. It forms the anterior part of the labyrinth, as a snail-like structure that is situated almost horizontally anterior to the VESTIBULAR LABYRINTH.Kinetofragminophorea: A class of ciliate protozoa. Prominent cytopharyngeal apparatus is characteristic of this class as is only a slight distinction between oral and somatic cilia.Hearing Aids: Wearable sound-amplifying devices that are intended to compensate for impaired hearing. These generic devices include air-conduction hearing aids and bone-conduction hearing aids. (UMDNS, 1999)Hearing Tests: Part of an ear examination that measures the ability of sound to reach the brain.Hearing Loss, Sensorineural: Hearing loss resulting from damage to the COCHLEA and the sensorineural elements which lie internally beyond the oval and round windows. These elements include the AUDITORY NERVE and its connections in the BRAINSTEM.Krukenberg Tumor: Mucocellular carcinoma of the ovary, usually metastatic from the gastrointestinal tract, characterized by areas of mucoid degeneration and the presence of signet-ring-like cells. It accounts for 30%-40% of metastatic cancers to the ovaries and possibly 1%-2% of all malignant ovarian tumors. The lesions may not be discovered until the primary disease is advanced, and most patients die of their disease within a year. In some cases, a primary tumor is not found. (From Dorland, 27th ed; Holland et al., Cancer Medicine, 3d ed, p1685)Hearing Loss, Bilateral: Partial hearing loss in both ears.Persons With Hearing Impairments: Persons with any degree of loss of hearing that has an impact on their activities of daily living or that requires special assistance or intervention.Audiometry: The testing of the acuity of the sense of hearing to determine the thresholds of the lowest intensity levels at which an individual can hear a set of tones. The frequencies between 125 and 8000 Hz are used to test air conduction thresholds and the frequencies between 250 and 4000 Hz are used to test bone conduction thresholds.Hearing Loss, Conductive: Hearing loss due to interference with the mechanical reception or amplification of sound to the COCHLEA. The interference is in the outer or middle ear involving the EAR CANAL; TYMPANIC MEMBRANE; or EAR OSSICLES.Hearing Loss, High-Frequency: Hearing loss in frequencies above 1000 hertz.Audiometry, Pure-Tone: Measurement of hearing based on the use of pure tones of various frequencies and intensities as auditory stimuli.Correction of Hearing Impairment: Procedures for correcting HEARING DISORDERS.Bipolar Disorder: A major affective disorder marked by severe mood swings (manic or major depressive episodes) and a tendency to remission and recurrence.