Distorted Speech and Binaural Speech Resynthesis Tests

Abstract

Monaural distorted speech and binaural speech resynthesis tests were used in detecting central auditory damage in 18 patients with intracranial expanding lesions. In the binaural speech resynthesis test the speech material first was divided acoustically by means of filters. One low-frequency part was presented to one ear and one high-frequency part to the other ear, after which the resynthesis mechanism was assessed binaurally. In the monaural test, the speech was fed through a combination of these two filters simultaneously after which the resynthesis ability of each ear was compared with the binaural discrimination scores. The monaural distorted speech test gave positive results, i.e. a discrimination loss was demonstrated for the contralateral ear only in patients with unilateral intracerebral temporal lobe lesions. The binaural speech resynthesis test gave negative results, i.e. a reduction in the ability to resynthesize speech was not demonstrated in any of the patients with expanding intracranial processes.