Biomedical subjects

D F Konkle

Publications and source records attributed to D F Konkle.

4 recordsLinked to original sources

PubMed1979

Meningitis and hearing loss in children.

The hospital records for 100 cases of meningitis in which acute audiometric data has been obtained were reviewed. The incidence of sensorineural hearing loss was found to be 6%. The severity of hearing impairment varied from mild to profound and was frequently bilateral and irreversible. Two-cases showed asymmetrical involvement, and in one case, there was subsequent improvement in threshold sensitivity. Factors that influenced the incidence of neurologic sequela included severity of the initial disease process, age of the patient, and duration of symptoms before diagnosis and treatment. We discuss the pathophysiologic mechanisms that may account for such hearing loss, and we emphasize the importance of early diagnosis and intensive antimicrobial therapy. Careful neurologic evaluation is required after recovery and must include periodic sequential audiometric testing.

Age Factors↗

PubMed1979

The development of middle-ear admittance in the hamster.

A high-frequency admittance meter was developed and used to study the maturation of physiological function in the middle ear of neonatal golden hamsters (Mesocricetus auratus). The middle-ear input admittance in the frequency range of 0.8-1.8 kHz was measured in animals ranging in age from 6 to 69 days postpartum. Admittance magnitude was found to increase steadily with age, beginning on day 16, to asymptotic values at each test frequency. There were no obvious differences in admittance growth rates within the range of frequencies tested. However, an analysis of the slopes of the admittance ma;nitude frequency response curves revealed an increase from 4.6 dB/octave for animals 25 days old or younger, to 6.3 dB/octave for all older animals. This difference between younger and older subjects indicates that the development of the middle ear in the golden hamster is more complex than a simple increase in pure compliance.

Acoustic Impedance Tests↗

PubMed1977

Intelligibility of time-altered speech in relation to chronological aging.

The Northwestern University Auditory Test Number 6 (NU-6) measure of speech discrimination was time compressed and presented to four age groups ranging from 54 to 84 years of age. Experimental stimuli were presented at sensation levels of 24, 32, and 40 dB to an equal number of right and left ears and male and female subjects. Results indicated that intelligibility decreased as a function of increasing time compression and age and decreasing sensation level. Changes in speech intelligibility associated with the aging process appear to be closely allied to changes in the temporal resolving power of the central auditory processing system.

Adult↗

PubMed1977

Central auditory imperception.

The development of clinically applicable techniques for the evaluation of hearing impairment caused by lesions of the central auditory pathways has increased clinical interest in the anatomy and physiology of these pathways. A conceptualization of present understanding of the anatomy and physiology of the central auditory pathways is presented. Clinical tests based on reduction of redundancy of the speech message, degradation of speech and binaural interations are presented. Specifically performance-intensity functions, filtered speech tests, competing message tests and time-compressed speech tests are presented with the emphasis on our experience with time-compressed speech tests. With proper use of these tests not only can central auditory impairments by detected, but brain stem lesions can be distinguished from cortical lesions.

Animals↗