Auditory Processing Performance of the Middle-Aged and Elderly: Auditory or Cognitive Decline?

BACKGROUND: Despite the well-established relationship between aging and auditory processing decline, identifying the extent to which age effect is the main factor on auditory processing performance remains a great challenge due to the co-occurrence of age-related hearing loss and age-related cognitive decline as potential confounding factors. PURPOSE: To investigate the effects of age-related hearing loss and working memory on the clinical evaluation of auditory processing of middle-aged and elderly. RESEARCH DESIGN: Cross-sectional study. STUDY SAMPLE: A total of 77 adults between 50 and 70 yr of age were invited to participate in the study. DATA COLLECTION AND ANALYSIS: The participants were recruited from a larger study that focused on the assessment and management of sensory and cognitive skills in elderly participants. Only participants with normal hearing or mild-to-moderate age-related hearing loss, with no evidence of cognitive, psychological, or neurological conditions were included. Speech-in-noise, dichotic digit, and frequency pattern tests were conducted as well as a working memory test. The hearing loss effect was investigated using an audibility index, calculated from the audiometric threshold. The performance on the digit span test was used to investigate working memory effects. Both hearing loss and working memory effects were investigated via correlation and regression analyses, partialling out age effects. The significance level was set at p < 0.05. RESULTS: The results demonstrated that, while hearing loss was associated to the speech-in-noise performance, working memory was associated to the frequency pattern and dichotic digit performances. Regression analyses confirmed the relative contribution of hearing loss to the variance in speech-in-noise and working memory test to the variance in frequency pattern and dichotic digit test performance. CONCLUSIONS: The performance decline of the elderly in auditory processing tests may be partially attributable to the working memory performance and, consequently, to the cognitive decline exhibited by this population. Mild-to-moderate hearing loss seems to affect performance on specific auditory processing tasks, such as speech in noise, reinforcing the idea that auditory processing disorder in the elderly might also be associated to auditory peripheral deficits

Descriptive discourse: topic familiarity and disfluencies

This investigation was undertaken to address questions about topic familiarity and disfluencies during oral descriptive discourse of adult speakers. Participants expressed more attributes when the topic was familiar than when it was unfamiliar. Fillers and lexical pauses were the most frequent disfluencies. The mean duration of each hesitation pause was 776 ms. The sum of hesitation pause durations was well correlated with the number of occurrences. Repetitions, hesitation pauses, and prolongations were shown to have the same role, which was distinct from the role of fillers. The type of analysis conducted in this investigation may be useful in distinguishing between normal and disordered speech production. Learning outcomes: The reader will obtain information about the differences between the number of propositions in familiar and unfamiliar oral descriptions. The reader will also become aware of the distribution of disfluencies in discourse categories employed by the participants in this investigation. (C) 2004 Elsevier Inc. All rights reserved.37648950