The role of the binaural test in filtered speech audiometry.

The value of the binaural resynthesis test administered according to Matzker's principle can be estimated only when a comparable monaural test can be used as a control. The most common positive finding in the filtered speech test is asymmetrical discrimination. Both parts of the message delivered to either ear must therefore have the same intelligibility in normal material. Binaural intelligibility is highly resistant to degenerative changes in the auditory system, for example. Positive findings in the binaural test are encountered frequently in brain stem lesions with vascular or traumatic aetiology.