[1] Sir Charles Gairdner Hosp, Dept Otorhinolaryngol Head & Neck Surg, Nedlands, WA 6009, Australia
[2] QEII Med Ctr, PathWest, Nedlands, WA, Australia
[3] Univ Western Australia, Dept Otolaryngol, Ear Sci Ctr, Perth, WA 6009, Australia
[4] Univ Western Australia, Dept Head & Neck Surg, Ear Sci Ctr, Perth, WA 6009, Australia