1. ANSI. ANSI S3.5-1997, Methods for the Calculation of the Speech Intelligibility Index. New York: American National Standards Institute, 1997.
2. Davis A. Hearing in Adults. London: Whurr Publishers, 1995.
3. Finney DJ. Probit Analysis. Cambridge: Cambridge University Press, 1971.
4. Kiessling J. Scaling methods for the selection, fitting and evaluation of hearing aids. In: Kollmeier B, ed. Psychoacoustics, Speech and Hearing Aids, Singapore: World Scientific, 1997; 297-306.
5. Kollmeier B, Hohmann V. Loudness estimation and compensation employing a categorical scale. In: Manley GA, Klump GM, Köppl C, Fastl H, Oeckinghaus H, eds. Advances in Hearing Research, Singapore: World Scientific, 1995; 441-51.