Effects of Age, Age-Related Hearing Loss, and Contralateral Cafeteria Noise on the Discrimination of Small Frequency Changes: Psychoacoustic and Electrophysiological Measures

The aim of the study was to examine central auditory processes compromised by age, age-related hearing loss, and the presentation of a distracting cafeteria noise using auditory event-related potentials (ERPs). In addition, the relation of ERPs to behavioral measures of discrimination was investigated. Three groups of subjects participated: young normal hearing, elderly subjects with normal hearing for their age, and elderly hearing-impaired subjects. Psychoacoustic frequency discrimination thresholds for a 1000-Hz pure tone were determined in quiet and in the presence of a contralateral cafeteria noise. To elicit ERPs, small frequency contrasts were presented with and without noise under unattended and attended conditions. In the attended condition, behavioral measures of d′ detectability and reaction times were also obtained. Noise affected all measures of behavioral frequency discrimination significantly. Except N1, all ERP components in the standard and difference waveforms decreased significantly in amplitude and increased in latency to the same degree in all three subject groups, arguing against a specific age-related sensitivity to the effects of contralateral background noise. For N1 amplitude, the effect of noise was different in the three subject groups, with a complex interaction of age, hearing loss, and attention. Behavioral frequency discrimination was not affected by age but deteriorated significantly in the elderly subjects with hearing loss. In the electrophysiological test, age-related changes occurred at various levels. The most prominent finding in the response to the standard stimuli was a sustained negativity (N2) following P2 in the young subjects that was absent in the elderly, possibly indicating a deficit in the inhibition of irrelevant information processing. In the attended difference waveform, significantly larger N2b and smaller P3b amplitudes and longer N2b and P3b latencies were observed in the elderly indicating different processing strategies. The pronounced age-related changes in the later cognitive components suggest that the discrimination of difficult contrasts, although behaviorally maintained, becomes more effortful in the elderl

Effects of Age, Age-Related Hearing Loss, and Contralateral Cafeteria Noise on the Discrimination of Small Frequency Changes: Psychoacoustic and Electrophysiological Measures

The aim of the study was to examine central auditory processes compromised by age, age-related hearing loss, and the presentation of a distracting cafeteria noise using auditory event-related potentials (ERPs). In addition, the relation of ERPs to behavioral measures of discrimination was investigated. Three groups of subjects participated: young normal hearing, elderly subjects with normal hearing for their age, and elderly hearing-impaired subjects. Psychoacoustic frequency discrimination thresholds for a 1000-Hz pure tone were determined in quiet and in the presence of a contralateral cafeteria noise. To elicit ERPs, small frequency contrasts were presented with and without noise under unattended and attended conditions. In the attended condition, behavioral measures of d′ detectability and reaction times were also obtained. Noise affected all measures of behavioral frequency discrimination significantly. Except N1, all ERP components in the standard and difference waveforms decreased significantly in amplitude and increased in latency to the same degree in all three subject groups, arguing against a specific age-related sensitivity to the effects of contralateral background noise. For N1 amplitude, the effect of noise was different in the three subject groups, with a complex interaction of age, hearing loss, and attention. Behavioral frequency discrimination was not affected by age but deteriorated significantly in the elderly subjects with hearing loss. In the electrophysiological test, age-related changes occurred at various levels. The most prominent finding in the response to the standard stimuli was a sustained negativity (N2) following P2 in the young subjects that was absent in the elderly, possibly indicating a deficit in the inhibition of irrelevant information processing. In the attended difference waveform, significantly larger N2b and smaller P3b amplitudes and longer N2b and P3b latencies were observed in the elderly indicating different processing strategies. The pronounced age-related changes in the later cognitive components suggest that the discrimination of difficult contrasts, although behaviorally maintained, becomes more effortful in the elderly

Survey on hearing aid use and satisfaction in Switzerland and their determinants

The purpose of this study was to investigate the efficiency of the Swiss hearing aid dispensing system, and to determine factors contributing to successful hearing aid provision. A national cross sectional survey was performed using a postal questionnaire with 8707 adult hearing aid owners (response rate 62%). To correct results for a potential non-response bias, 193 randomly selected non-respondents were contacted by telephone. Data on hearing loss and type of hearing aid were provided by the hearing aid dispensing practice. Logistic regression analyses were performed to identify determinants of non-regular use and dissatisfaction. Eighty-five percent used their device(s) regularly, 12% only occasionally and 3% never. Eighty percent were satisfied with their aids. Non-regular use of hearing aids was significantly associated with age, gender, regional language, total duration of use, type of amplification, hearing aid category, hearing loss, and dissatisfaction with and difficulties in managing the aid. Dissatisfaction was associated with regional language, total duration of use, difficulties in managing the aid, and non-regular use. It was concluded that rates of regular hearing aid use and satisfaction are high in Switzerland

Late auditory evoked potentials in elderly long-term hearing-aid users with unilateral or bilateral fittings

This study investigated the effects of long-term unilateral and bilateral amplification on central auditory processing in elderly people with symmetrical hearing loss using late auditory evoked potentials. It was hypothesized that in the unilateral setting stimulation of the aided ear would yield an acclimatization effect with larger amplitudes and shorter latencies of the components P1, N1 and P2 compared to those of the unaided ear. Auditory evoked potentials were elicited by 500, 1000 and 2000 Hz pure tones at 55, 70 and 85 dB SPL presentation level delivered either to the left or right ear. Unilaterally and bilaterally fitted experienced hearing-aid users and a control group of normally hearing adults, all aged at least 60 years, participated. The responses of the unilateral hearing-aid users did not differ significantly for any of the components P1, N1 or P2 between the aided and unaided ears, but a significant interaction between ear and frequency was present for P2 amplitudes. P2 amplitudes were significantly smaller for the 0.5- and 1-kHz stimuli and tended to be larger for the 2-kHz stimulus in the aided ear suggesting an acclimatization effect. Larger P2 amplitudes were observed in the unilaterally fitted group, which was interpreted as a correlate of more effortful auditory processing in unilaterally fitted people

Survey on hearing aid outcome in Switzerland: associations with type of fitting (bilateral/unilateral), level of hearing aid signal processing, and hearing loss.

The present investigation further analysed results of a previously reported survey with a large sample of hearing aid owners (Bertoli et al, 2009) to determine the individual and technological factors related to hearing aid outcome. In particular the associations of hearing loss, level of signal processing, and fitting type (bilateral versus unilateral fitting) with hearing aid use, satisfaction with and management of the aid were evaluated. A sub-group with symmetrical hearing loss was analysed (n = 6027). Regular use was more frequent in bilateral users and in owners of devices with more complex signal processing, but the strongest determinant of regular use was severity of hearing loss. Satisfaction was higher in the group wearing simple devices, while fitting type and degree of hearing loss had no influence on satisfaction rates. Moderate and severe hearing loss was associated more frequently with poor management of the aid than mild hearing loss. It was concluded that bilateral amplification and advanced signal processing features may contribute to successful hearing aid fitting, but the resulting differences must be considered to be relatively small