[1] Natl Hosp Neurol & Neurosurg, Dept Neurootol, London WC1N 3BG, England
[2] Natl Hosp Neurol & Neurosurg, Neuropsychol Dept, London WC1N 3BG, England
[3] Natl Hosp Neurol & Neurosurg, Dept Radiol, London WC1N 3BG, England
[4] Inst Child Hlth, Acad Unit Audiol Med, London, England
[5] UCL, Inst Neurol, Stroke Res Grp, London WC1E 6BT, England
[6] UCL, Audiol Med, Inst Child Hlth, London, England
[7] Univ London, London WC1E 7HU, England
[8] Univ Connecticut, DCP Comm Ctr, Storrs, CT USA