Pole-zero modeling of the middle ear based on acoustic reflectance measurements

Sarah Robinson, Jont Allen

Research output: Contribution to journalConference articlepeer-review


Fitting poles and zeros to complex acoustic reflectance (CAR) data using a "rational approximation method" (Gustavsen & Semlyen, 1999) allows for a precise parameterization of complex real-ear measurements. CAR is measured using a foam-tipped probe sealed in the ear canal, containing a microphone and receiver. From the complex pressure response to a broadband stimulus, the acoustic impedance and reflectance of the middle ear can be calculated as functions of frequency. The goal of this work is to establish a quantitative connection between the fitted polezero locations and underlying physical properties of the CAR and impedance of the middle ear. It was found that (1) the contribution of the ear canal may be approximated as the lossless all-pass component of the factored reflectance fit, (2) individual CAR magnitude variations for normal middle ears in the 1 to 4 kHz range give rise to closely-placed pole-zero pairs, and (3) properties of the pole-zero fit may differ between normal and pathological middle ears. Pole-zero fitting allows for concise characterization of individual CAR measurements, providing a foundation for modeling individual and pathological variations of middle ears.

Original languageEnglish (US)
Article number030093
JournalProceedings of Meetings on Acoustics
StatePublished - 2013
Externally publishedYes
Event21st International Congress on Acoustics, ICA 2013 - 165th Meeting of the Acoustical Society of America - Montreal, QC, Canada
Duration: Jun 2 2013Jun 7 2013

ASJC Scopus subject areas

  • Acoustics and Ultrasonics


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