Central auditory information processing in patients with bilateral auditory cortex lesions.

Severe auditory cognitive disorders in 10 patients who had bilateral lesions either to the auditory cortex and/or auditory radiations were studied audiologically with special attention to residual hearing. This auditory cognitive problem is called "auditory agnosia or cortical deafness". Our study revealed that auditory information processing for pure tones, monosyllable discrimination, environmental sound perception, and auditory comprehension is commonly but differently affected by bilateral lesions of auditory cortex or auditory radiation. In summary, these patients can discriminate loudness of pure tones and some environmental sounds but cannot clearly perceive any sounds of monosyllables and sentences. Generally their residual hearing is useful for auditory awareness and is often enhanced by lip reading.