Ninety-three patients with histolofically or radiolofically confiemd unilateral vestibular schwannomas were recruited. Audiological testing for retrocochelar pathology was undertaken. Patients' hospital records were examined for previous audiological and radiological results.
The audiometric configuration was designated as one of the following normal, sloping, low frequency, peak, through or falt. A sloping sensorneural audiometric configuration was present in 68 pec cent of cases. No significant correlation was found between tumour size and average pure tone threshold 500 HZ to 4000 HZ, optimum discrimination score or interaural differences for wave V. Ninety-one per cent of cases had abnoramalities on auditory evoked potential; 92 per cent of cases showed abnormalities on stapedial reflex testing.
The limitations of audiologica testing in the investigation of patients with suspected unilateral vestibular schwannomas are discussed. A protocol for the investigation of such patients is presented.