title: Experimental Analysis of the Mechanism of Hearing under Water.
abstract: The mechanism of human hearing under water is debated. Some suggest it is by air conduction (AC), others by bone conduction (BC), and others by a combination of AC and BC. A clinical bone vibrator applied to soft tissue sites on the head, neck, and thorax also elicits hearing by a mechanism called soft tissue conduction (STC) or nonosseous BC. The present study was designed to test whether underwater hearing at low intensities is by AC or by osseous BC based on bone vibrations or by nonosseous BC (STC). Thresholds of normal hearing participants to bone vibrator stimulation with their forehead in air were recorded and again when forehead and bone vibrator were under water. A vibrometer detected vibrations of a dry human skull in all similar conditions (in air and under water) but not when water was the intermediary between the sound source and the skull forehead. Therefore, the intensities required to induce vibrations of the dry skull in water were significantly higher than the underwater hearing thresholds of the participants, under conditions when hearing by AC and osseous BC is not likely. The results support the hypothesis that hearing under water at low sound intensities may be attributed to nonosseous BC (STC).
authors.affiliation: Department of Communication Disorders, Sackler Faculty of Medicine, Tel Aviv University, The Chaim Sheba Medical Center, 52621 Tel Hashomer, Israel.
authors.forename: Shai
authors.initials: S
authors.lastname: Chordekar
authors.affiliation: Department of Communication Disorders, Sackler Faculty of Medicine, Tel Aviv University, The Chaim Sheba Medical Center, 52621 Tel Hashomer, Israel.
authors.forename: Liat
authors.initials: L
authors.lastname: Kishon-Rabin
authors.affiliation: Ozen Kashevet Hearing Clinic, 6 Ben Maimon Street, 92261 Jerusalem, Israel; Department of Communication Disorders, Hadassah Academic College, 37 Haneviim Street, P.O. Box 1114, 91010 Jerusalem, Israel.
authors.forename: Leonid
authors.initials: L
authors.lastname: Kriksunov
authors.affiliation: Department of Communication Disorders, Hadassah Academic College, 37 Haneviim Street, P.O. Box 1114, 91010 Jerusalem, Israel; Speech & Hearing Center, Hebrew University School of Medicine, Hadassah Medical Center, Kiryat Hadassah, P.O. Box 12000, 91120 Jerusalem, Israel.
authors.forename: Cahtia
authors.initials: C
authors.lastname: Adelman
authors.affiliation: Department of Medical Neurobiology (Physiology), Institute for Medical Research Israel-Canada, Hebrew University, Hadassah Medical School, P.O. Box 12272, 91120 Jerusalem, Israel.
authors.forename: Haim
authors.initials: H
authors.lastname: Sohmer
mesh_terms: D000328:Adult; D001309:Auditory Threshold; D001844:Bone Conduction / Q000502:physiology*; D003051:Cochlea / Q000502:physiology*; D016057:Evoked Potentials, Auditory, Brain Stem / Q000502:physiology; D005260:Female; D006309:Hearing / Q000502:physiology*; D006320:Hearing Tests; D006801:Humans; D008297:Male; D013016:Sound; D014732:Vibration; D014867:Water
chemical_list: D014867:Water