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J Am Acad Audiol 2001; 12(03): 150-154
DOI: 10.1055/s-0042-1745591
Original Article

Estimating the Location of Probe Microphones Relative to the Tympanic Membrane

Lydia Storey
National Acoustic Laboratories, Chatswood, Australia
,
Harvey Dillon
National Acoustic Laboratories, Chatswood, Australia
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Abstract

This experiment investigated the accuracy with which the location of a probe tip relative to the tympanic membrane can be estimated by means of standing waves. The ear canal length of each ear of six adult subjects was measured with a probe tube using a tactile method. A 6–kHz warble tone was then generated, and the position of the standing wave notch in the ear canal was determined using a probe microphone by noting the place where the sound pressure level was at a minimum. The distance of the notch from the tympanic membrane was then calculated. The mean distance of the notch from the tympanic membrane was found to be 14.1 mm. It was concluded that this technique is reliable and suitable for clinical use when it is important that the probe tube be placed within a known distance of the eardrum for accurate measurement of real-ear aided gain.

Abbreviations: REAG = real-ear aided gain

Keywords

Probe microphone - real-ear aided gain - standing waves


Publikationsverlauf

Artikel online veröffentlicht:
28. Februar 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

  • Chan JCK, Geisler CD. (1990). Estimation of eardrum acoustic pressure and of ear canal length from remote points in the canal. J Acoust Soc Am 87:1237–1247.
  • Dillon H. (2000). Hearing Aids. Sydney: Boomerang Press.
  • Dirks DD, Kincaid GE. (1987). Basic acoustic considerations of ear canal probe measurements. Ear Hear 8 (Suppl 5):60S-67S.
  • Gerling IJ, Engman SM. (1991). Comparison of probe tube placement methods in real ear measurements. Hear Instr 42:20–22.
  • Gilman S, Dirks D. (1986). Acoustics of ear canal measurement of eardrum SPL in simulators. J Acoust Soc Am 80:783–793.
  • Salvinelli F, Maurizi M, Calamita S, D’Alatri L, Capelli A, Carbone A. (1991). The external ear and the tympanic membrane. A three-dimensional study. Scand Audiol 20:253–256.
  • Sullivan RF. (1988). Probe microphone placement near the tympanic membrane. Hear Instr 39:43–44, 60.
  • Voss SE, Allen JB. (1994). Measurement of acoustic impedance and reflectance in the human ear canal. J Acoust Soc Am 95:372–384.