[Distorted Freiburg Speech Test].

In 107 patients with different types of hearing loss (air conduction, sensorineural and combined) we ascertained the monaural discrimination loss of monosyllables with the help of the normal and distorted Freiburg speech test. It was evident that the quotient obtained from the measured discrimination is a very good and useful measure to characterise the ability to analyse the peripheral hearing system. Compared with normal hearing individuals and patients with air conduction hearing loss or combined loss of hearing, persons with perception hearing loss show a much greater and more divergent quotient. The discrimination of distorted speech depends more on age than that of normal speech; however, it is considerably reduced from the sixth decade of life onwards. The distortion test offers the expertising the possibility of improved assessment of speech discrimination by workers in a noisy environment in case of unfavourable hearing conditions, but it is also of considerable importance in fitting hearing aids and in the diagnosis of acoustic tumours.