Under pressure in the middle ear is thought to be important in the pathogenesis of chronic otitis media with effusion and its sequelae, but the cause of the under pressure and the mechanisms responsible for regulation of the normal middle ear pressure are a matter of debate. Numerous studies have examined the effect of large pressure changes on the ear; however, the ear's sensitivity to smaller pressure changes has received little attention. This study examines the sensitivity of the ear to atmospheric air pressure changes induced in the external ear canal. It is concluded that the normal ear is a very sensitive pressure receptor, and that the sensation is probably registered by stretch receptors in the tympanic membrane. Pathological changes in the tympanic membrane are associated with impaired baroreceptor function. The implications of these findings in the physiology of the ear and the regulation of middle ear pressure are discussed.

Third-octave sound analysis was performed on the snoring sounds of nine subjects with obstructive sleep apnoea (OSA) and 18 with simple snoring. Both groups demonstrated a large low frequency peak in linear sound levels at around 80 Hz. However, the OSA group displayed a substantially larger high frequency sound component. We utilized this fact in the development of an acoustic index (Hawke Index: HI) which describes the ratio between the overall A-weighted and linear sound levels for the recorded snoring sound of each subject [HI = dB(A)/dB(SPL) for Lmax]. There was a significant positive correlation between the apnoea/hypopnoea index and the HI (r = 0.73, t = 5.3, 25df, P < 0.001). If a value of 0.90 or greater was taken as diagnostic of OSA, the HI exhibited 67% sensitivity, 100% specificity, 100% positive and 86% negative predictive accuracy. With further development, we believe this acoustic phenomena may have a role as a screening test in the diagnosis of OSA.

A case report of verrucous carcinoma in the ear of a patient subject to persistent discharge from that ear for more than 30 years is presented. The histology conformed to that in Ackerman's classic description and a literature search revealed that this is only the second case of this disease reported. The patient was treated surgically followed by radiotherapy and was well 18 months later.

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Microfractures of the temporal bone have been recognized for more than seventy years and occur in certain well-defined areas of the otic capsule. The etiology and significance of these microfractures has been debated since their discovery. The most commonly held theory is that they result from stresses within the otic capsule that develop with growth. An alternative explanation might be that they result from masticatory stress placed upon the temporal bone.Fifty serially-sectioned temporal bones from the Ontario Temporal Bone Bank were examined in this study for the presence of microfractures. Our findings as to the most common sites of microfractures agree with previous studies.It is proposed that the constant stress placed upon the petrous temporal bone by the act of mastication is directed by the anatomy of the external, middle and inner ear through certain definite pathways, including the Fallopian canal, the bony semicircular canals and the cochlea. The most common sites of these fractures represent sites of weakness in the path of these directed forces within the otic capsule, and the statistically significant increase in the number of fractures with age lends support to the masticatory stress theory.