Processing of Temporal Fine Structure as a Function of Age

Abstract

Objectives-The purpose of this study was to determine whether the processing of temporal fine structure diminishes with age, even in the presence of relatively normal audiometric hearing. Temporal fine structure processing was assessed by measuring the discrimination of inter-aural phase differences (IPDs). The hypothesis was that IPD discrimination is more acute in middle-aged observers than in older observers but that acuity in middle-aged observers is nevertheless poorer than in young adults.Design-Two experiments were undertaken. The first measured discrimination of 0-and π-radian inter-aural phases as a function of carrier frequency. The stimulus was a 5-Hz sinusoidally amplitude modulated tone where, in the signal waveform, the inter-aural phase of the carrier was inverted during alternate modulation periods. The second experiment measured IPD discrimination at fixed frequencies. The stimulus was a pair of tone pulses where, in the signal, the trailing pulse contained an IPD. A total of 39 adults with normal audiograms below 2000 Hz participated: 15 younger, 12 middle-aged, and 12 older.Results-Experiment 1 showed that the highest carrier frequency at which a π-radian IPD could be discriminated from the diotic, 0-radian standard was significantly lower in middle-aged listeners than young adults, and lower still in older listeners. Experiment 2 indicated that middle-aged listeners were less sensitive to IPDs than young adults at all but the lowest frequencies tested. Older listeners, as a group, had the poorest thresholds.Conclusions-These results suggest that deficits in temporal fine structure processing are evident in the pre-senescent auditory system. This adds to the accumulating evidence that deficiencies in some aspects of auditory temporal processing emerge relatively early in the aging process. It is possible that early-emerging temporal processing deficits manifest themselves in challenging speechin-noise environments.

Effects of Age and Hearing Loss on the Processing of Auditory Temporal Fine Structure

“…Scores on the TFS-LF task were not significantly correlated with absolute thresholds at the test frequency. These results confirm those of Ross et al (2007) and Grose and Mamo (2010), and indicate that the decline in sensitivity to binaural TFS with increasing age is already apparent by middle age. Füllgrabe et al (2015) used the TFS-LF task with their young and older groups with matched (normal) audiograms, as described above.…”

Spatial Selective Auditory Attention in the Presence of Reverberant Energy: Individual Differences in Normal-Hearing Listeners

“…While we hypothesized that we would see such differences, we expected them to correlate with age, reflecting degradations in the fidelity with which the sensory system encodes fine temporal details even in pre-senescent (middle-aged) listeners. This expectation was driven by previous studies of middle-aged listeners that reveal deficits in physiological responses evoked by changes in interaural cues (Ross et al 2007;Ross 2008;Wambacq et al 2009), as well as psychophysical studies that reveal deficits in performance by middle-aged listeners (Grose et al 2006;Helfer and Vargo 2009;Grose and Mamo 2010). Despite this, on our task, we found that age did not predict individual differences in performance.…”

“…Anecdotally, even middle-aged listeners report problems with selective auditory attention (Helfer and Freyman 2008;Wambacq et al 2009). A recent study shows that interaural phase discrimination is poorer in middle-aged listeners (40-55 years) than in young listeners (18-27 years; it is poorer still in older listeners aged 63-75), suggesting that temporal fine structure processing degrades at an earlier age than is often assumed for other forms of presbycusis (Grose and Mamo 2010). Other recent studies also show that middle-aged listeners perform worse than younger listeners in some tasks, particularly those involving temporal processing (Grose et al 2009;Helfer and Vargo 2009).…”

“…This combination of behavioral and physiological evidence suggests that a task that relies on spatial selective auditory attention may be particularly sensitive in revealing effects of early aging on auditory perception. This study measured spatial selective auditory attention in listeners ranging in age from young adulthood to early middle age (ages studied in Helfer and Vargo 2009;Grose and Mamo 2010); this choice allowed us to study a adult listeners over a large age span (almost four decades) while avoiding confounding factors such as reduced cognitive function (which is apt to contribute to differences in performance in listeners older than those in our cohort; e.g., see Pichora-Fuller and Singh 2006;Sheldon et al 2008a, b;Arlinger et al 2009). We reasoned that any early aging effects on the auditory system were most likely to be revealed in conditions in which fine temporal cues (that are used to compute ITD) are not robustly represented in the acoustic inputs a listener hears.…”

Development of a method for determining binaural sensitivity to temporal fine structure

“…There is increasing evidence that both hearing loss and age can adversely affect the processing of TFS information Moore 2007, 2011;Grose and Mamo 2010;Moore et al 2012, Moore, Vickers, andMehta 2012;Füllgrabe 2013;Füllgrabe and Moore 2014;Füllgrabe, Moore, and Stone 2015). This has led to interest in the development of tests that could be used in the clinic or in large-scale research studies to assess monaural and binaural sensitivity to TFS.…”