Faculty Bibliography

The remarkable susceptibility of the inner ear of the patas monkey (Erythrocebus patas) to the ototoxic action of dihydrostreptomycin (DHSM) (and streptomycin (SM)) is well established in this paper and affords a rare example of a species-specific reaction to a restricted class of compounds within the aminoglycoside group of antibiotics. In a series of experiments, behavioral and morphological observations together provided the following profile of DHSM ototoxicity in the patas monkey: Sudden onset of hearing loss beginning after 7-9 weeks of treatment; Substantial, though often partial, hearing impairment beginning at the high frequencies and progressing with or without continued treatment to the low frequencies; In the inner ear, a corresponding and selective loss of nerve fibers and of outer hair cells, relative to inner hair cells, beginning in the base of the cochlea and proceeding toward the apex; Continued and progressive loss of hearing for several months after cessation of drug treatment; and Non-auditory effects in some animals on the kidney and vestibular system. Results from control experiments confirmed this special relationship between the patas monkey and DHSM: Other nonhuman primates (macaques and vervet monkeys) were essentially unaffected by DHSM; The patas showed no equivalent sensitivity to other aminoglycosides such as kanamycin or to other forms of ototraumatic insult such as intense noise.

Condyloma acuminatum is one of four types of common human verrucous lesions that are of viral etiology. Also known as "moist wart," condyloma acuminatum is most often seen on the mucosal surfaces of the anogenital area. However, occurrences in the mucosal lined areas of the head and neck region are quite rare. Since 1901, 30 cases of condylomatous lesions have been reported in the upper aerodigestive tract, occurring mainly in the various regions of the oral cavity. Eighteen of the cases were confirmed by histopathologic documentation, while the remainder were anecdotal. We have recently encountered six new cases of condyloma acuminatum, verified by histologic examination. One occurred on the tongue, another in the tonsillar fossa, one in the hypopharynx and three on the vocal cords. We present these cases and review the previously reported cases. In addition, we will discuss the differential diagnosis of these lesions, and their importance to the practicing otolaryngologist.

Recent progress on the development of an ear-level digital hearing aid is described. The work includes development of a body-wearable digital hearing aid and a computer-based hearing evaluation system that exploits the flexibility afforded by digital signal processing. The prescriptive criteria and fitting procedure used with the digital hearing aid are described briefly. Design considerations in the development of VLSI chips for an ear-level unit are discussed.

Speech audibility may be defined as that proportion of a speech spectrum which is above a person's threshold. To optimize speech audibility with a hearing aid, several measures are needed. These include quantification of a speech spectrum, measures of hearing sensitivity, and measures of the "real ear" gain of the hearing aid. Some procedural factors must be considered to obtain adequate measures in a typical clinical setting. Those considered here are: (1) a modified Articulation Index to quantify a speech spectrum, (2) specification of hearing sensitivity with a narrowband sound field reference where the out-of-band rejection rate of the sound field stimulus is greater than twice the slope of the hearing loss, and (3) use of functional gain (measured directly or estimated using earphone and sound field results provided that the sound field stimulus has the required characteristics for measuring hearing sensitivity in the sound field) as a measure of the real ear gain of the hearing aid. Guidelines are given for the practical measurement of speech audibility in a typical clinical setting. The guidelines are appropriate for all measures of real ear gain including those obtained with all probe tube systems.

Controversy exists regarding the appropriateness of offering all residents training in stapes surgery due to dwindling case loads in residency programs nationally. A recent study indicated poorer results for stapes surgery performed by residents than results obtained by practicing otologists. One hundred consecutive stapedectomies performed by residents over a three-year period at our institution were reviewed retrospectively, with the objective of determining whether these results should be generalized.