Wideband absorbance tympanometry using pressure sweeps: system development and results on adults with normal hearing

J Acoust Soc Am. 2008 Dec;124(6):3708-19. doi: 10.1121/1.3001712.

Abstract

A system with potential for middle-ear screening and diagnostic testing was developed for the measurement of wideband energy absorbance (EA) in the ear canal as a function of air pressure, and tested on adults with normal hearing. Using a click stimulus, the EA was measured at 60 frequencies between 0.226 and 8 kHz. Ambient-pressure results were similar to past studies. To perform tympanometry, air pressure in the ear canal was controlled automatically to sweep between -300 and 200 daPa (ascending/descending directions) using sweep speeds of approximately 75, 100, 200, and 400 daPas. Thus, the measurement time for wideband tympanometry ranged from 1.5 to 7 s and was suitable for clinical applications. A bandpass tympanogram, calculated for each ear by frequency averaging EA from 0.38 to 2 kHz, had a single-peak shape; however, its tympanometric peak pressure (TPP) shifted as a function of sweep speed and direction. EA estimated at the TPP was similar across different sweep speeds, but was higher below 2 kHz than EA measured at ambient pressure. Future studies of EA on normal ears of a different age group or on impaired ears may be compared with the adult normal baseline obtained in this study.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Acoustic Impedance Tests / methods*
  • Acoustic Impedance Tests / standards
  • Acoustic Stimulation*
  • Adult
  • Air Pressure
  • Artifacts
  • Calibration
  • Ear Canal / physiology*
  • Ear, Middle / physiology*
  • Feasibility Studies
  • Hearing*
  • Humans
  • Reference Values
  • Reproducibility of Results
  • Signal Processing, Computer-Assisted
  • Time Factors
  • Young Adult