His research interests cover mouse functional genomics, including the use of large-scale mouse mutagenesis and comparative genomic analysis to study the genetic basis of disease and to develop pre-clinical disease models. A particular focus has been the use of mouse models to study the molecular basis of genetic deafness. Along with Karen Steel, he discovered myosin VIIA as the gene underlying the shaker1 mutant, one of the first deafness genes to be identified. Subsequently, he has developed interests in the protein complexes that are involved with stereocilia elongation in hair cells in the inner ear. In addition, over the last ten years he has led a substantial research effort in the genetics of otitis media or glue ear, a common cause of hearing loss in children, employing mouse models to elaborate the key genetic pathways involved and develop novel therapeutic strategies.