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J Am Acad Audiol 2001; 12(10): 534-544
DOI: 10.1055/s-0042-1745644
Original Article

Effects of Release Time and Directionality on Unilateral and Bilateral Hearing Aid Fittings in Complex Sound Fields

Marni L. Novick
Department of Speech Pathology and Audiology, The University of Iowa, Iowa City, Iowa
,
Ruth A. Bentler
Department of Speech Pathology and Audiology, The University of Iowa, Iowa City, Iowa
,
Andrew Dittberner
Department of Speech Pathology and Audiology, The University of Iowa, Iowa City, Iowa
,
Gregory A. Flamme
Department of Speech Pathology and Audiology, The University of Iowa, Iowa City, Iowa
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Abstract

In studies to date, the effectiveness of the directional microphone has been investigated independently of the signal processing scheme used in the hearing aid. In addition, the number and placement of the background noise speakers can create an advantage for a particular polar pattern (i.e., cardioid, supercardioid, and hypercardioid) in any laboratory design. With these considerations in mind, the purpose of this investigation was twofold: (1) to determine the effect of different amplitude-compression release times on speech perception ability in noise, measured with directional microphone hearing aids, and (2) to determine the impact of environment (classroom vs anechoic chamber) on those measures. Ten subjects with mild to moderate sensorineural hearing loss participated. Using an eight-speaker complex sound field, speech perception was assessed in an anechoic chamber and a typical classroom environment. None of the release times resulted in superior performance in either the anechoic or classroom environment.

Abbreviations: ANOVA = analysis of variance, BTE = behind the ear, HINT = Hearing in Noise Test, ITE = in the ear, KEMAR = Knowles Electronics Mannikin for Acoustic Research, RBCF = randomized blocks completely factorial, RT = reverberation time, SNR = signal-to-noise ratio, SPIN = Speech Perception in Noise (test), TR = release time

Keywords

Complex sound field - directional microphone - hearing aids - release time


Publication History

Article published online:
07 March 2022

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

Thieme Medical Publishers, Inc.
333 Seventh Avenue, 18th Floor, New York, NY 10001, USA

 

  • REFERENCES

  • American National Standards Institute. (1996a). American National Standards for Specifications of Audiometers. (ANSI S3.6–1996). New York: ANSI.
  • American National Standards Institute. (1996b). American National Standards for Specification of Hearing Aid Characteristics. (ANSI S3.22–1996). New York: ANSI.
  • American National Standards Institute. (1997). The Calculation of Articulation Index. (ANSI S3.5–1997). New York: ANSI.
  • Bentler RA, Duve M. (2000). Comparison of hearing aids over the twentieth century. Ear Hear 21:6252–639.
  • Bentler RA, Nelson JA. (1997). Assessing release-time options in a two-channel AGC hearing aid. Am J Audiol 6:43–51.
  • Bentler RA, Niebuhr DP, Getta JP, Anderson CV. (1993a). Longitudinal study of hearing aid effectiveness. I: objective measures. J Speech Hear Res 36:808–819.
  • Bentler RA, Niebuhr DP, Getta JP, Anderson CV. (1993b). Longitudinal study of hearing aid effectiveness. II: subjective measures. J Speech Hear Res 36:820–831.
  • Bess FH, Tharpe AM. (1986). An introduction to unilateral sensorineural hearing-impaired children. Ear Hear 7:3–13.
  • Bilger RC, Neutzel JM, Rabinowitz WM, Rzeczkowski C. (1984). Ear Hear 27:32–48.
  • Hawkins DB, Yacullo WS. (1984). Signal-to-noise ratio advantage of binaural hearing aids and directional microphones under different levels of reverberation. J Speech Hear Disord 49:278–286.
  • Kalikow DN, Stevens KN, Elliot LI. (1977). Development of a test of speech intelligibility in noise using sentence materials with controlled word predictability. J Acoust Soc Am 61:1337–1351.
  • Kirk RE. (1995). Experimental Design: Procedures for the Behavioral Sciences. Pacific Grove, CA: Brooks/Cole, 587–615.
  • Konkle D, Schwartz D. (1981). Binaural amplification: a paradox. In: Bess FH, Freeman BA, Sinclair S, eds. Amplification in Education. Washington, DC: Alexander Graham Bell Association.
  • Neuman AC, Bakke MH, Mackersie C, Hellman S, Levitt H. (1995). Effect of release-time in compression hearing aids: paired-comparison judgments of quality. J Am Acoust Soc 98:3182–3187.
  • Neuman AC, Bakke MH, Mackersie C, Hellman S, Levitt H. (1998). The effect of compression ratio and release time on the categorical rating of sound quality. -J Am Acoust Soc 103:2273–2281.
  • Nilsson M, Soli SD, Sullivan J. (1994). Development of a hearing in noise test for the measurement of speech reception threshold. J Acoust Soc Am 95:1085–1099.
  • Pumford JM, Seewald RC, Scollie SD, Jenstad LM. (2000). Speech recognition with in-the-ear and behind-the-ear dual-microphone hearing instruments. J Am Acad Audiol 11:23–25.
  • Ricketts T, Dhar S. (1999). Comparison of performance across three directional hearing aids. J Am Acad Audiol 10:180–189.
  • Schum DJ. (1996). Speech understanding in background noise. In: Valente M, ed. Hearing Aids: Standards, Options, and Limitations. 1st Ed. New York: Thieme Medical Publishers, 179–194.
  • Valente M. (1996). Hearing Aids: Standards, Options, and Limitations. New York: Thieme Medical Publishers, 298–326.
  • Valente M. (1998). The bright promise of microphone technology. Hear J 51:10–16.
  • Valente M, Fabry D, Potts LG. (1995). Recognition of speech in noise with hearing aids using dual microphones. J Am Acad Audiol 6:440–449.
  • Valente M, Sweetow R, May A. (1999). Using microphone technology to improve speech recognition. High Performance Hearing Solutions 3:10–13.
  • Veit I, Sander H. (1987). Production of spatially limited “diffuse” sound field in an anechoic room. J Audio Eng Soc 35:138–145.
  • Yost WA. (1997). The cocktail party problem: forty years later. In: Gilkey RH, Anderson TR, eds. Binaural and Spatial Hearing in Real and Virtual Environments. Mahwah, NJ: Lawrence Erlbaum Associates, 329–347.