TY - JOUR
T1 - Measurements and calculations on the simple up-down adaptive procedure for speech-in-noise tests
AU - Smits, Cas
AU - Houtgast, Tammo
PY - 2006
Y1 - 2006
N2 - The simple up-down adaptive procedure is a common method for measuring speech reception thresholds. It is used by the Dutch speech-in-noise telephone screening test [National Hearing test; Smits and Houtgast Ear Hear. 26, 89-95 (2005)]. The test uses digit triplets to measure the speech reception threshold in noise by telephone (SRTTn). About 66 000 people took this test within four months of its introduction and details were stored of all individual measurements. Analyses of this large volume of data have revealed that the standard deviation of SRTTn estimates increases with hearing loss. This paper presents a calculation model which - using an intelligibility function as input - can determine the standard deviation of SRTTn estimates and the bias for the simple up-down procedure. The effects of variations in the slope of the intelligibility function, the guess rate, the starting level, the heterogeneity of the speech material, and the possibilities of optimizing SRTTn measurements were all explored with this model. The predicted decrease in the standard deviation of SRTTn estimates as a result of optimizing the speech material was confirmed by measurements in 244 listeners. The paper concludes by discussing possibilities for optimizing the development of comparable tests.
AB - The simple up-down adaptive procedure is a common method for measuring speech reception thresholds. It is used by the Dutch speech-in-noise telephone screening test [National Hearing test; Smits and Houtgast Ear Hear. 26, 89-95 (2005)]. The test uses digit triplets to measure the speech reception threshold in noise by telephone (SRTTn). About 66 000 people took this test within four months of its introduction and details were stored of all individual measurements. Analyses of this large volume of data have revealed that the standard deviation of SRTTn estimates increases with hearing loss. This paper presents a calculation model which - using an intelligibility function as input - can determine the standard deviation of SRTTn estimates and the bias for the simple up-down procedure. The effects of variations in the slope of the intelligibility function, the guess rate, the starting level, the heterogeneity of the speech material, and the possibilities of optimizing SRTTn measurements were all explored with this model. The predicted decrease in the standard deviation of SRTTn estimates as a result of optimizing the speech material was confirmed by measurements in 244 listeners. The paper concludes by discussing possibilities for optimizing the development of comparable tests.
UR - http://www.scopus.com/inward/record.url?scp=33748552072&partnerID=8YFLogxK
U2 - https://doi.org/10.1121/1.2221405
DO - https://doi.org/10.1121/1.2221405
M3 - Article
C2 - 17004483
SN - 0001-4966
VL - 120
SP - 1608
EP - 1621
JO - Journal of the Acoustical Society of America
JF - Journal of the Acoustical Society of America
IS - 3
ER -