Selective loos of timbre perception for keyboard and percussion instruments following a right temporal lesion

We report the case of a 65-year-old man WDK, who experienced selective loss of timbre perception for keyboard and percussion instruments following a right temporal stroke comprising the anterior superior and medial gyrus and parts of the insular region. Formerly an avid listener to music, the sound of an orchestra appeared to be "flat" to him. WDK and a matched control subject underwent a detailed neuropsychological test battery covering basic auditory function (audiometry and just notable difference for pitch shifts), specific auditory function (recognition of environmental sounds), specific musical functions like discrimination of pitch, interval, contour, rhythm and metre, recognition of familiar melodies, emotional responsiveness, perception of timbre and auditory spectral analysis. While WDK displayed no deficits in primary auditory function, the test battery revealed a selective impairment in the perception of timbre of keyboard and percussion instruments which could be traced to a deficit in discriminating rapid changes of the spectral composition of a tone. Hence, these findings demonstrate the existence of highly specific neural networks underlying isolated aspects of timbre perception in the right anterior temporal lobe.