Faculty Bibliography

Hearing impairment and related cochlear histopathologic changes were evaluated in experimental animals after treatment with aminoglycoside antibiotics or exposure to intense sound. In the course of treatment with kanamycin, neomycin, or dihydrostreptomycin, permanent hearing loss in monkeys and guinea pigs occurred first at the high frequencies and progressed toward the lows. Exposure to different octave bands of noise at 120 dB SPL in monkeys and chinchillas produced permanent hearing loss at frequencies related to the spectral characteristics of the octave band. In most instances loss of outer hair cells was substantially greater than that of inner hair cells. In fact, the pattern and location of missing outer hair cells on the basilar membrane were most often correlated with threshold shifts of 50 dB or less. Generally inner hair cell loss was observed when the threshold shift was greater than 50 dB. Our data support the place principle and the inference that the outer hair cells are essential for hearing from threshold to about 50 dB SL. The inner hair cells, if functioning normally, apparently take over above that level. Although there is little doubt that such a generalization will, in the long term, be found to have been greatly oversimplified, there is every reason to believe that a combination of behavioral and morphologic procedures, as used in this study, will play an important part in elucidating the differences in functional significance of the two types of hair cells.

Fantasy stories were composed by 153 undergraduates (93 females, 60 males) who also responded to the Bem Sex Role Inventory. The fantasy stories were collected by group administration of a Thematic Apperception Test. The stories were content analyzed along 17 imagery categories. Males and females differed significantly in ten of these categories. The results indicate a substantial continuity of sex differences in fantasy content between earlier decades and the mid 1970s. However, women had relatively more imagery of a self-assertive, pleasurable, and careerist nature than had been found in earlier studies. The fantasies of sex-typed persons were more situation-bound and more sexual than those of androgynous persons. Sex-typed persons appear to experience limitations in fantasy production which parallel their limitations in overt behavior.

We discuss aphonia in children, secondary to laryngeal obstruction, with regard to the development of a voice, speech, and language system that can be an effective and efficient means of communication while obstruction persists and a precursor to good voice and speech habits if and when the laryngeal function is reestablished. Several methods were considered. A technique of esophageal voice training for children was developed and implemented, which combined the aspects of normal language learning with the mechanical aspects of esophageal voice production. Results showed rapid learning in a 2 1/2-year-old child with severe juvenile laryngeal papillomatosis and normal speech and language at the age of 4 years when laryngeal function returned. A second technique, a communication board, was used with a 4-year-old child with total subglottic stenosis and brain damage.

Search of the literature thus far indicates no prior description of rhinophyma occuring in tuberous sclerosis. There have been numerous reports of the usual skin lesion, adenoma sebaceum, together with the associated manifestations of severe mental retardation and convulsive seizures. In a 27-year-old woman, full-blown, severely deforming rhinophyma had its onset one year prior to her hospital admission. The family, horrified by her appearance, desired surgical intervention. The report includes a review of the literature and a description of the patient and of the surgical technique employed. The question of the desirability and difficulty involved in skin grafting is discussed, as are the microscopic findings and postoperative course. Particular attention is directed toward differential diagnosis and associated findings

The growth function of the acoustic stapedius reflex was measured in subjects with normal hearing and sensorineural hearing loss of cochlear origin. The effects of age and magnitude of hearing loss were controlled. Activating stimuli were 500, 1000, and 2000 Hz tones and broadband noise. Stapedius muscle activity was inferred from acoustic impedance measures in the contralateral ear. The mean growth functions for tones were essentially linear in log-log plots with the rate of growth equal for the two groups. The mean growth function for the noise signal was curvilinear for the normal hearing groud had linear for the hearing loss group. Comparison of slope functions derived from the fitted data indicated that the rate of reflex growth for the noise signal, over a limited range above reflex threshold, is greater in ears with cochlear lesions than normal ears. For higher level noise signals, however, the rate of reflex growth is similar for normal and pathological ears. The effect of a cochlear lesion on the input-output function of the cochlea for both tonal and noise stimuli is to maintain the rate of reflex growth but shift the function along the intensity axis of a tonal signal and the response axis for a noise signal.

Tympanometry was performed before and after producing specific lesions in the middle ears of cats. The lesions selected for study included stapes fixation, ossicular discontinuity, and scarred tympanic membranes. Stapes fixation resulted in marked increases in middle ear impedance, easily detected with tympanometry. Ossicular discontinuity resulted in complex tympanometric shapes which were easily accounted for by simple interactions between acoustic resistance and reactance. The complex shapes that occurred in normal and abnormal ears with pressure changing from negative to positive resulted from more complicated interactions. Large surgical incisions in the posterior-superior quadrant of the eardrum were quite visible at otoscopy but could not be detected tympanometrically one month after surgery.

The differential contribution of the inner hair cells (IHC) and the outer hair cells (OHC) in the mammalian cochlea to hearing sensitivity was assessed in six behaviorally-trained guinea pigs by comparing audiograms preadministration and postadministration of kanamycin, an antibiotic that predominantly destroys guinea pig OHC while leaving the IHC structurally unchanged. The results support the hypothesis that only the IHC of the cochlea responds to tones approximately 50 to 60 dB above the threshold of the intact cochlea.

This study investigated the effects of two 'frozen' narrow-band waveforms with different waveform envelopes 50 msec in duration and centered at 250 Hz, on temporal masking at short masking intervals and, further, assessed the effects of phase shifts on backward and forward masking. Four normal-hearing experienced Ss detected a monaurally presented 250-Hz tone burst, 12 msec in duration, that either preceded, occurred simultaneously with, or followed a burst of the narrow-band noise. A 2IFC technique was used with a transformed up-down procedure for threshold estimation. The masking intervals from onset of masker to onset of tonal pulse ranged from -30 to +70 msec. The 3 phasic conditions for the signal were in-phase, 90 degrees out-of-phase, and 180 degrees out-of-phase. Results of this experiment substantiated the data of other researchers who have shown greater backward than forward masking at short masking intervals and greater masking was found for all simultaneous conditions than for any of the backward or forward masking conditions. In addition, differences between the two noise waveforms, as well as the phase shifts, had a significant effect on the thresholds obtained for the backward and forward masking conditions, as well as for the simultaneous masking conditions. Criterion change and waveform storage are discussed as possibly having an effect up these variables