title: Human ultrasonic hearing is induced by a direct ultrasonic stimulation of the cochlea.
abstract: Ultrasound can be perceived by bone-conduction. The cochlear basal turn is involved in processing bone-conducted ultrasound (BCU) information. Previous studies have suggested that ultrasonic perception is induced by ultrasound itself. In contrast, it has also been suggested that a lower frequency sound is generated in non-linear process during the transmission pathway to the cochlea to induce an auditory sensations. To address this issue, we assessed cisplatin-induced changes in BCU sensitivity at 27, 30 and 33kHz in 20 participants (40 ears) who were scheduled to undergo cisplatin chemoradiation therapy. Following the treatment, 62.5% ears were diagnosed with hearing loss according to the criteria of the American Speech-Language-Hearing Association. As expected, significant increases in sensitivity threshold were observed for air-conducted sounds ranging from 8 to 14kHz. In contrast, the BCU threshold significantly decreased after the treatment. Considering that both air-conducted high-frequency sound and BCU are perceived in the cochlear basal turn, these findings indicate that ultrasonic perception is independent of hearing a lower frequency sound generated in non-linear process. In addition, our findings support the hypothesis that ultrasound itself induces ultrasonic perception in the cochlea. The observed cisplatin-induced increase in BCU sensitivity may be explained by hypersensitivity associated with outer hair cells' disorder.
authors: Department of Otolaryngology-Head and Neck Surgery, Nara Medical University, 840 Shijo-cho, Kashihara Nara 634-8522, Japan. tokayasu@naramed-u.ac.jp
authors: Tadao
authors: T
authors: Okayasu
authors: Tadashi
authors: T
authors: Nishimura
authors: Akinori
authors: A
authors: Yamashita
authors: Osamu
authors: O
authors: Saito
authors: Fumi
authors: F
authors: Fukuda
authors: Shuichi
authors: S
authors: Yanai
authors: Hiroshi
authors: H
authors: Hosoi
mesh_terms: D000161:Acoustic Stimulation; D000328:Adult; D000368:Aged; D000388:Air; D000970:Antineoplastic Agents / Q000009:adverse effects; D001307:Auditory Perception / Q000187:drug effects; D001844:Bone Conduction; D002945:Cisplatin / Q000009:adverse effects; D003051:Cochlea / Q000187:drug effects / Q000503:physiopathology*; D005260:Female; D006309:Hearing / Q000187:drug effects; D034381:Hearing Loss / Q000139:chemically induced / Q000503:physiopathology; D006801:Humans; D008297:Male; D008875:Middle Aged; D014465:Ultrasonics
chemical_list: D000970:Antineoplastic Agents; D002945:Cisplatin