Related Experiment Video
Updated: May 20, 2026
The Microscopic Transcanal Approach in Stapes Surgery Revisited
Published on: February 16, 2022
How the cross-sectional discontinuity between ear canal and probe affects the ear canal length estimation
Makram Zebian1, Johannes Hensel, Thomas Fedtke
1Physikalisch-Technische Bundesanstalt, Braunschweig, Germany. makram.zebian@ptb.de
Abstract:
Many ear canal probes both deliver and measure sound via narrow tubes. This study investigates the effect of the cross-sectional discontinuity at the interface between ear canal models and the connecting tubes of a commercially available otoacoustic emission probe on the "acoustically" estimated cavity lengths. Rigid cavities having the same length but different diameters were produced, and modeled by the finite element method. Cavities with a diameter larger than 8 mm had acoustic lengths that considerably overestimated the real geometry. A length correction was derived, which, in most applications, compensates for the measurement errors emerging from the discontinuity effects.
Related Concept Videos
01:10Interference: Path Lengths
Two special sources may be considered when they are in phase. This can be easily achieved by feeding the two sources from the same source. An example would be synchronizing the two speakers by feeding them with the same source, such as the sound waves produced by a tuning fork. This setup ensures that the two sources have the same frequency and are...
01:06Echo
Imagine the sound is reflected back to the ears. Assuming that the source is very close to the human, the difference between hearing the two sounds—the emitted sound and the reflected sound—may be more than the minimum time for perceiving distinct sounds. If this is the case, then the...
01:10Design Example: Measuring Distance Between Two Points with Obstructions