1. Head and Neck Cancer Centre; University College London Hospital National Health Service Foundation Trust; London UK
2. Department of Epidemiology & Public Health; Health Behaviour Research Centre, University College London; London UK
3. Regional Medical Physics Department; Institute of Cellular Medicine, Freeman Hospital; Newcastle-upon-Tyne UK
4. Speech and Language Therapy; Imperial College Healthcare National Health Service Trust; London UK
5. Guy's Hospital London; London UK
6. Division of Language and Communication Science; City University London; London UK