Acoustical changes in radical ear surgery

ABSTRACT

The external ear acts as a resonant system that adds about 12 dB at frequency around 2000 Hz at the tympanic membrane which helps to reduce the loss of acoustic energy around that frequency. 60 ears [33 had radical cavities and 27 were normal] were examined, and the frequency resonance curve was recorded. It is found that radical mastoid cavities have resonant frequency at 4.28 KHz compared to 1.95 KHz in normal ears. It is concluded that radical mastoid surgery favors higher speech frequencies which are important for speech intelligibility, while intact canal wall technique [acts as normal ear] favors less important lower frequencies