Human ossicular-joint flexibility transforms the peak amplitude and width of impulsive acoustic stimuli.
J Acoust Soc Am
; 143(6): 3418, 2018 06.
Article
in En
| MEDLINE
| ID: mdl-29960477
ABSTRACT
The role of the ossicular joints in the mammalian middle ear is still debated. This work tests the hypothesis that the two synovial joints filter potentially damaging impulsive stimuli by transforming both the peak amplitude and width of these impulses before they reach the cochlea. The three-dimensional (3D) velocity along the ossicular chain in unaltered cadaveric human temporal bones (N = 9), stimulated with acoustic impulses, is measured in the time domain using a Polytec (Waldbronn, Germany) CLV-3D laser Doppler vibrometer. The measurements are repeated after fusing one or both of the ossicular joints with dental cement. Sound transmission is characterized by measuring the amplitude, width, and delay of the impulsive velocity profile as it travels from the eardrum to the cochlea. On average, fusing both ossicular joints causes the stapes velocity amplitude and width to change by a factor of 1.77 (p = 0.0057) and 0.78 (p = 0.011), respectively. Fusing just the incudomalleolar joint has a larger effect on amplitude (a factor of 2.37), while fusing just the incudostapedial joint decreases the stapes velocity on average. The 3D motion of the ossicles is altered by fusing the joints. Finally, the ability of current computational models to predict this behavior is also evaluated.
Full text:
1
Database:
MEDLINE
Main subject:
Acoustic Stimulation
/
Ear Ossicles
/
Hearing
/
Joints
Type of study:
Prognostic_studies
Language:
En
Journal:
J Acoust Soc Am
Year:
2018
Type:
Article
Affiliation country:
United States