Speech intelligibility test

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A speech intelligibility test is an examination that tests a person's ability to hear and understand speech. Speech intelligibility tests are methods of audiometry .

In most speech intelligibility tests, spoken words are played to the person to be examined through headphones at a defined volume. The test person then provides information about what he has heard. The discrepancy to the text actually played allows conclusions to be drawn about the hearing ability and speech understanding.

Test categories

Syllable tests

Syllable tests consist of playing single (meaningless) syllables or numbers. The test person should repeat the syllables and the test management evaluates the answers according to the scheme understood / not understood .

Word tests

Speech audiogram form with normal curves (numerals and monosyllables)

The most frequently used word test is the Freiburg word test described by Karl Heinz Hahlbrock in 1953 (Freiburg speech audiogram, in short: speech audiogram ). Numbers and monosyllabic nouns are offered via headphones (or loudspeakers). Numeral words are very easy to understand, they can be recognized correctly even at comparatively low sound pressure levels. With normal hearing, half of the numerals are correctly repeated at just under 20 dB. Monosyllabic nouns can only be pronounced correctly if every sound ( phoneme ) has been recognized. With normal hearing, the monosyllabic nouns can only be fully understood from around 50 dB.

A hearing-impaired person needs correspondingly higher sound pressure levels to understand the words. In the case of a sound sensation disorder , however, not all monosyllabic words are understood even at the optimal level. This is called a loss of discrimination.

The test series of the Freiburg test consists of two-digit, mostly four-syllable number words (10 groups of 10 numbers each) and monosyllabic words such as Ring , Spott , Farm , Hang , which are offered in groups of 20 words each. The word groups are played at different levels and the number of words correctly repeated is given in percent. The result is entered in the form of curves for numerical comprehension and for word comprehension in a standardized form. This form can be used to read the hearing loss for numbers , the discrimination loss and the optimal intensity as key figures .

Advantages of the Freiburg word test are the easily reproducible conditions, the exact definition of the test and its results and decades of experience. The test is u. a. standardized in DIN 45621-1. The disadvantage is the restriction to monosyllables and numerals and the lack of definitions of the signal- to -noise ratio .

In general, word tests have little to do with real language. Impairments of speech understanding caused by speech-like background noises such as B. arise in a restaurant or at a party, can be simulated in speech audiometry by playing a defined background noise (e.g. Döring test ).

Sentence tests

Sentence tests consist of whole sentences, they come closer to the conditions of normal life than a word test. Sentence tests are spoken in whole sentences on sound carriers and played back exactly as they are. Examples of German-language sentence tests are the Oldenburg sentence test , the Göttingen sentence test , the HSM sentence test with and without background noise and the Marburg sentence comprehension test .

English language sentence tests

The SPIN test (Speech Perception In Noise) is very widespread in the Anglo-Saxon language area . It consists of eight lists of 50 sentences each. The last word of each sentence represents the test object. The sentences are constructed in such a way that the test object can be guessed either particularly well or particularly poorly from the context. One speaks of 'high predictability' (HP) and 'low predictability' (LP) sentences. The frequency of the HP and LP sentences is the same. The test person has to reproduce the sentences as a whole, but only the hits and errors of the test words are evaluated.


The most important purpose of the speech intelligibility tests is the prescription and fitting of hearing aids . In Germany, the Freiburg word test is required together with the application of the APHAB questionnaire for the regulation. Speech audiometry is also indispensable for assessing hearing loss.

Individual evidence

  1. Dieter Mrowinski: audiometry: a guide for practical hearing test , Georg Thieme Verlag, Stuttgart 2006, ISBN 9783131180032 , pp 51-61.