Speech intelligibility as a function of time compression, age, word position, and signal-to-noise ratio


  • Anne Schlueter Institute of Hearing Technology and Audiology, Jade University of Applied Sciences, Oldenburg, Germany
  • Inga Holube Institute of Hearing Technology and Audiology, Jade University of Applied Sciences, Oldenburg, Germany
  • Ulrike Lemke Phonak AG, Staefa, Switzerland


Among other parameters, speech intelligibility depends on the rate of speech. Therefore, variation of time compression might be useful for adjusting the threshold of 50% intelligibility in speech in noise tests at fixed positive signal-to-noise ratios (SNRs). Speech rate can be modified with uniform and non-uniform algorithms. Uniform algorithms delete equally spaced segments, while non-uniform algorithms first characterize the structure of the speech and then increase the speech rate dependent on the classification. Referring to studies using fast speech, age effects have to be taken into account. To investigate fast speech in a German speech intelligibility test, sentences speeded to different time compressions were presented at different SNRs and intelligibility measurements were conducted with young and elderly normal-hearing listeners. The outcomes were used to calculate SNR-dependent discrimination functions. The results showed increasing SNRs for 50% intelligibility with increasing time compression. As expected, young listeners reached higher intelligibility than elderly listeners at equal time compressions and SNRs for 50% intelligibility were shifted to lower values. Additionally, increasing the speech rate affected word intelligibility in dependence on the words’ position within the sentences. These differences in intelligibility led to shallower slopes of the discrimination functions and could possibly constrain the accuracy of the test.


Adams, E. M. and Moore, R. E. (2009). “Effects of Speech Rate, Background Noise, and Simulated Hearing Loss on Speech Rate Judgment and Speech Intelligibility in Young Listeners” J. Am. Acad. Audiol., 20, 28-39.

Boetsma, P. and Weenink, D. (2009). “Praat – doing phonetics by computer (version 5.1.15)” www.praat.org (last viewed 08/02/2011).

Covell, M., Withgott, M. and Slaney, M. (1998). “Mach1: Nonuniform Time-Scale Modificaton of Speech” in Proceedings of the 1998 IEEE International Conference on Acoustics, Speech, and Signalprocessing, Seattle, 1, 349-352.

Gordon-Salant, S. and Fitzgibbons, P. J. (2001). “Sources of Age-Related Recognition Difficulty for Time-Compressed Speech” J. Speech, Lang., and Hear. Res., 44, 709-719.

Gordon-Salant, S. and Fitzgibbons, P. J. (2004). “Effects of stimulus and noise rate variability on speech perception by younger and older adults” J. Acoust. Soc. Am., 115, 1808-1817.

Gordon-Salant, S. and Friedman, S. A. (2011). “Recognition of Rapid Speech by Blind and Sighted Older Adults” J. Speech, Lang., and Hear. Res, 54, 622-631.

Moulines, E. and Charpentier, F. (1990). “Pitch-synchronous waveform processing techniques for text-to-speech synthesis using diphones” Speech Comm., 9, 453– 467.

Nilsson, M., Soli S. D. and Sullivan, J. A. (1994). “Development of the Hearing In Noise Test for the measurement of speech reception thresholds in quiet and in noise” J. Acoust. Soc. Am., 95, 1085-1099.

Schlueter, A. (2007) “Perzeptive Beurteilung von Sprache im Störgeräusch”, Master’s thesis, Oldenburg University.

Schneider, B. A., Daneman, M. and Murphy, D. R. (2005). “Speech Comprehension Difficulties in Older Adults: Cognitive Slowing or Age-Related Changes in Hearing?” Psychology and Aging, 20, 261-271.

Tun, P. A. (1998). “Fast noisy speech: age differences in processing rapid speech with background noise” Psychology and Aging, 13, 424-434.

Versfeld, N. J and Dreschler, W. A. (2002). “The relationship between the intelligibility of time-compressed speech and speech in noise in young and elderly listeners” J. Acoust. Soc. Am., 111, 401-8.

Wagener, K. and Brand T. (2005). “Sentence intelligibility in noise for listeners with normal hearing and hearing impairment: Influence of measurement procedure and masking parameters” Int. J. Audiol., 44, 144-156.

Wagener, K., Kühnel, V. and Kollmeier, B. (1999). “Entwicklung und Evaluation eines Satztests für die deutsche Sprache I: Design des Oldenburger Satztests” Z. Audiol., 38, 4-15.

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How to Cite

Schlueter, A., Holube, I., & Lemke, U. (2011). Speech intelligibility as a function of time compression, age, word position, and signal-to-noise ratio. Proceedings of the International Symposium on Auditory and Audiological Research, 3, 191–198. Retrieved from http://proceedings.isaar.eu/index.php/isaarproc/article/view/2011-23



2011/1. Indicators of hearing impairment and measures of speech perception