J Am Acad Audiol 2001; 12(09): 462-470
DOI: 10.1055/s-0042-1745634
Original Article

Effect of Spectral Shaping and Content on Loudness Discomfort

Ruth A. Bentler
Department of Speech Pathology and Audiology, The University of Iowa, Iowa City, Iowa
John A. Nelson
Widex Office of Research in Clinical Amplification, Long Island City, New York
› Institutsangaben


The purpose of this investigation was to study the impact of spectral shape and content on thresholds of discomfort (TD) for listeners with normal hearing and listeners with hearing loss. Secondary to that purpose was to quantify binaural summation at high intensities across complex stimulus conditions for both groups of listeners. Forty subjects (20 with normal hearing, 20 with hearing loss) participated. Complex acoustic stimuli (multitone and continuous discourse) were filtered to have four spectral shapes: (1) flat spectrum, (2) long-term average speech spectrum, (3) reverse long-term average speech spectrum, and (4) theTD contour derived for each subject from pure-tone TD obtained with eight pure tones from 250 to 4000 Hz. The results suggest that (1) TD for complex stimuli are lower for subjects with hearing loss compared with those with normal hearing, suggesting increased loudness summation with this population; (2) binaural summation of approximately 6 dB (independent of stimulus type, filter shape, or spectral content), indicating that a correction of similar magnitude for bilateral hearing aid fittings is appropriate; and (3) TD obtained at 750, 1500, and 3000 Hz accounted for approximately 60 percent of the variance in the complex TD measures, suggesting that TD at these frequencies be used to set the output obtained from a hearing aid with a 90–dB pure-tone sweep as the input stimulus.

Abbreviations: ANOVA = analysis of variance, FIR = finite-impulse response, FS = flat spectrum, LTASS = long-term average speech spectrum, OSPL90 = output obtained from a hearing aid with a 90–dB pure-tone sweep as the input stimulus, R-LTASS = reverse long-term average speech spectrum, TD = threshold(s) of discomfort, TD contour = spectrum derived from TDs obtained with eight pure tones from 250 to 4000 Hz


Artikel online veröffentlicht:
07. März 2022

© 2001. American Academy of Audiology. This article is published by Thieme.

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  • American National Standards Institute. (1992). Testing Hearing Aids with a Broad-band Noise Signal. (ANSI 3.42). New York: ANSI.
  • American National Standards Institute. (1996a). American National Standard Specification of Hearing Aid Characteristics. (ANSI S3.22). New York: ANSI.
  • American National Standards Institute. (1996b). American National Standard Specifications for Audiometers. (ANSI S3.6). New York: ANSI.
  • Bentler R, Abbas P, Pavlovic C. (1990). A signal processing scheme for output limitation. Acta Otolaryngol Suppl (Stockh) 469:230–235.
  • Bentler R, Cooley L. (2001). An examination of several characteristics that affect the prediction of OSPL90 in hearing aids. Ear Hear 22:65–74.
  • Bentler R, Pavlovic CV. (1989). Comparison of discomfort levels obtained with pure tones and multi-tone complexes. J Acoustic Soc Am 86:126–132.
  • Bonding P. (1979a). Critical bandwidth in patients with hearing loss induced by salicylates. Audiology 18:133–144.
  • Bonding P. (1979b). Critical bandwidth in Meniere’s disease. Audiology 18:197–211.
  • Bonding P. (1979c). Critical bandwidth in presbycusis. Scand Audiol 8:43–50.
  • Cox RM. (1981). Using LDLs to establish hearing aid limiting levels. Hear Instr 32:16–20.
  • Dillon H, Storey L. (1998). The National Acoustic Laboratories’ procedure for selecting the saturation sound pressure level of hearing aids: theoretical derivation. Ear Hear 19:255–266.
  • Dirks D, Kamm C. (1976). Psychometric functions for loudness discomfort and most comfortable loudness levels. J Speech Hear Res 19:613–627.
  • Fortune T, Preves D. (1992). Acoustic and hearing aid circuit variables affecting the tolerability of aided impulsive-type sounds. J Am Acad Audiol 5:307–316.
  • Franks J, Beckman N. (1985). Rejection of hearing aids: attitudes of a geriatric population. Ear Hear 6:161–166.
  • Hall J, Harvey A. (1985). Diotic loudness summation in normal and impaired hearing. J Speech Hear Res 28:445–448.
  • Hawkins D. (1981). The effect of signal type on the loudness discomfort level. Ear Hear 1:34–41.
  • Hawkins DB. (1984). Selection of a critical electroacoustic characteristics: SSPL90. Hear Instr 35:28–32.
  • Hawkins DB, Prosek RA, Walden BE, Montegomery A. (1987). Binaural loudness summation in the hearing impaired. J Speech Hear Res 30:37–43.
  • Kamm C, Dirks DD, Mickey MR. (1978). Effects of sensorineural hearing loss on loudness discomfort level and most comfortable level judgments. J Speech Hear Res 21:668–681.
  • Morgan DE, Wilson RH, Dirks DD. (1974). Loudness discomfort level: selected methods and stimuli. JAcoust Soc Am 56:577–581.
  • Mueller H, Grimes A. (1987). Amplification systems for the hearing impaired. In: Alpiner J, McCarthy P, eds. Rehabilitative Audiology: Children and Adults. Baltimore: Williams & Wilkins, 115–160.
  • Pascoe DP. (1988). Clinical measurements of the auditory dynamic range and their relation to formulate for hearing aid gain. In: Jensen JH, ed. Hearing Aid Fitting: Theoretical and Practical Views. Copenhagen: Stougaard Jensen, 129–154.
  • Scharf B, Hellman RP. (1966). Model of loudness summation applied to impaired ears. J Acoust Soc Am 40:71–78.
  • Shapiro I. (1979). Evaluation of relationship between hearing threshold and loudness discomfort level in sensorineural hearing loss. J Speech Hear Disord 64:31–36.
  • Sherman D. (1962). The merits of backward playing of connected speech in the scaling of voice quality disorders. J Speech Hear Disord 27:172–177.
  • Skinner MW. (1988). Hearing Aid Evaluation. Englewood Cliffs, NJ: Prentice-Hall.
  • Storey L, Dillon H, Yeend I, Wigney D. (1998). The National Acoustic Laboratories procedure for selecting the saturation sound pressure level of hearing aids: experimental validation. Ear Hear 19:267–279.
  • Warner R. Bentler R. (In press). Relationship of perceived quality dimensions to thresholds of discomfort. J Speech Hear Discord.
  • Zwicker E, Flottorp G, Stevens S. (1957). Critical bandwidth in loudness summation. J Acoust Soc Am 29:548–557.