Abstract
Objective:
To explain a clinical observation: a notch in the stimulus spectrum during transient evoked otoacoustic emission measurement in ears with secretory otitis media.
Methods:
The effects of tympanic under-pressure were investigated using a pressure chamber. A model of the ear canal was also studied.
Results:
Tympanic membrane reflectance increased as a consequence of increased stiffness, causing a notch in the stimulus spectrum. In an adult, the notch could be clearly distinguished at an under-pressure of approximately -185 daPa. The sound frequency of the notch corresponded to a wavelength four times the ear canal length. The ear canal of infants was too short to cause a notch within the displayed frequency range. The notch was demonstrated using both Otodynamics and Madsen equipment.
Conclusion:
A notch in the otoacoustic emission stimulus spectrum can be caused by increased stiffness of the tympanic membrane, raising suspicion of low middle-ear pressure or secretory otitis media. This finding is not applicable to infants.
To explain a clinical observation: a notch in the stimulus spectrum during transient evoked otoacoustic emission measurement in ears with secretory otitis media.
Methods:
The effects of tympanic under-pressure were investigated using a pressure chamber. A model of the ear canal was also studied.
Results:
Tympanic membrane reflectance increased as a consequence of increased stiffness, causing a notch in the stimulus spectrum. In an adult, the notch could be clearly distinguished at an under-pressure of approximately -185 daPa. The sound frequency of the notch corresponded to a wavelength four times the ear canal length. The ear canal of infants was too short to cause a notch within the displayed frequency range. The notch was demonstrated using both Otodynamics and Madsen equipment.
Conclusion:
A notch in the otoacoustic emission stimulus spectrum can be caused by increased stiffness of the tympanic membrane, raising suspicion of low middle-ear pressure or secretory otitis media. This finding is not applicable to infants.
| Original language | English |
|---|---|
| Pages (from-to) | 897-901 |
| Journal | Journal of Laryngology and Otology |
| Volume | 126 |
| Issue number | 9 |
| DOIs | |
| Publication status | Published - 2012 |
Subject classification (UKÄ)
- Oto-rhino-laryngology