Factors influencing use of hearing aids.

A follow-up questionnaire was mailed to new hearing aid users. The questionnaire responses of 430 persons, 73% of the sample, were related to age, audiometric, and hearing aid evaluation data obtained at the time of fitting. Reported usage of the aids was also analyzed in terms of the type of fitting and according to length of postfitting training. Further, the reasons for limited or nonuse were tabulated. The population in the present study, in comparison with that of previous investigations, was characterized by relatively young age and predominantly noise-induced, sensorineural type hearing loss, with mild hearing loss for speech; these factors led to a high proportion of selective amplification fittings. Reported overall use did not differ among the types of aids. Overall use declined with increasing age, and the majority of persons in this population used their aids selectively rather than on a full-time basis. Length of postfitting training appeared to increase hearing aid use. Mean audiometric and hearing aid evaluation data remained relatively constant across four usage categories: "always," "often," "occasionally," and "never." Excessive background noise and lack of need constituted 63% of the reasons given for limited use or nonuse.

The reliability and validity of the comfort level method of setting hearing aid gain.

The comfort level method (Carhart, 1946) probably is the most widely used procedure for setting the acoustic gain of hearing aids. A series of experiments were conducted to determine the test-retest reliability of the comfort level method and the relationship between the comfort settings established in a clinical test suite and the comfort settings utilized in more realistic daily listening situations. Adults with bilateral sensorineural hearing impairments were subjects. The results suggest that the comfort level method has good test-retest reliability for most clinical purposes. Further, clinically established comfort settings may accurately represent typical daily-use settings if the input level used to establish the comfort settings in the clinical environment is 70 dB SPL.

Masking level difference for speech: effects of ear dominance and age.

A comparison was made of right and left ear discrimination of monosyllables presented with competing 'cocktail party' in conditions of signal monaural-noise monaural, and signal monaural-noise binaural and in-phase interaurally. The effects of these conditions were compared in 20 normal children aged 5-6 years, 40 normal young adults and 20 adults aged 66-76 years. The magnitudes of right and left ear masking level differences (MLDs) were compared at each age level. (1) MLDs occurred for all three age groups; (2) for the two adult age groups, mean right ear scores exceeded mean left ear scores in the case of monaural noise presentation, although the difference was significant only for the young adults; (3) no interaural difference appeared for the children, and (4) marked variability of the magnitude of the MLDs occurred among subjects of all three age groups.

Measurement of the acoustic reflex without a pressure seal.

Obtaining a hermetic seal in the external auditory canal is often a major obstacle in impedance audiometry. In the present study, the acoustic reflex threshold was determined for three groups of subjects, first with and then without a pressure-tight seal. It was found that for subjects with normal hearing or sensorineural hearing loss and normal tympanograms, 96% of the measurements obtained without a pressure seal were within 5 dB of those obtained with a seal. Among the subjects who exhibited negative middle ear pressure, the acoustic reflex could be measured consistently at the point of maximum compliance, while no response was observed without a pressure seal.