Faculty Bibliography

A series of experiments is described tracing the development and application of adaptive paired-comparison testing to the prescriptive fitting of hearing aids. The equipment needed to implement the test procedures became progressively more complex with each new experiment, leading to the development of a digital master hearing aid

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.

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.

Removal of the soft palate can cause marked functional deficit in deglutition and phonation. Most commonly, treatment of this deformity with prosthetic obturation has been less than ideal. Numerous reconstructive techniques have met with only partial success, while deforming distant structures. We will present a technique of reconstruction of the soft palate by use of a superiorly based pharyngeal flap. It has been used successfully in five patients who underwent soft palatectomy for malignant disease. The flaps have been the full width of the pharynx and extended down to the esophageal inlet. Viability of the flap is excellent, and the donor site is allowed to heal by secondary intention. Excellent function has been achieved in all cases with no compromise of oncological principles

The signal-to-noise ratio of brainstem auditory evoked responses (BAER) can be greatly enhanced by use of optimal digital filtering before averaging. This permits accurate assessment of auditory nerve status every 5 to 10 seconds, making real-time intraoperative monitoring possible. The major advantages yielded by real-time monitoring--in our experience thus far--have been identification of potentially adverse functional consequences of apparently uneventful surgical maneuvers, reducing postoperative dysfunction, early indication of potential for improved clinical function, and potential identification and localization of neural tissue in the face of absent surgical landmarks. Examples of these advantages will be provided from case studies, and the possibility that real-time monitoring may improve ability to preserve hearing will be discussed

There has been widespread use of periodic dilatations in the management of subglottic stenosis. However, some authorities have questioned the value in the overall rehabilitation of patients affected by this disorder. The first phase of this study included fourteen large dogs in which acute subglottic lesions were created by use of a high-speed electric drill and electrocautery. Twelve animals served as the experimental group and two animals were controls. Obstructing lesions developed in all the animals within 7 to 21 days. When at least a 50% obstruction developed in an animal, a treatment plan was instituted that included at least weekly dilatation, removal of granulations, and administration of intralesional steroids and/or systemic steroids and antibiotics. The two control animals became totally obstructed and were killed. Varying degrees of subglottic stenosis developed in all twelve experimental animals after 8 weeks of dilatation, but none required a tracheotomy. These twelve animals were then subjected to 8 additional weeks of dilatation and antibiotics, and supplemental steroids were used in some animals from this study. It can be concluded that early periodic dilatation and granulation removal in the acutely injured subglottis is effective in prevention of severe stenosis, late periodic dilatations in chronic subglottic stenosis are not helpful in further alleviation of obstruction, the concomitant use of antibiotics and systemic steroids did not appreciably prevent or alter the development of subglottic stenosis, and the concomitant use of intralesional steroids appeared to be of benefit in the management of chronic acquired subglottic stenosis