Informational Masking in Normal-Hearing and Hearing-Impaired Listeners Measured in a Nonspeech Pattern Identification Task

Abstract

Individuals with sensorineural hearing loss (SNHL) often experience more difficulty with listening in multisource environments than do normal-hearing (NH) listeners. While the peripheral effects of sensorineural hearing loss certainly contribute to this difficulty, differences in central processing of auditory information may also contribute. To explore this issue, it is important to account for peripheral differences between NH and these hearing-impaired (HI) listeners so that central effects in multisource listening can be examined. In the present study, NH and HI listeners performed a tonal pattern identification task at two distant center frequencies (CFs), 850 and 3500 Hz. In an attempt to control for differences in the peripheral representations of the stimuli, the patterns were presented at the same sensation level (15 dB SL), and the frequency deviation of the tones comprising the patterns was adjusted to obtain equal quiet pattern identification performance across all listeners at both CFs. Tonal sequences were then presented at both CFs simultaneously (informational masking conditions), and listeners were asked either to selectively attend to a source (CF) or to divide attention between CFs and identify the pattern at a CF designated after each trial. There were large differences between groups in the frequency deviations necessary to perform the pattern identification task. After compensating for these differences, there were small differences between NH and HI listeners in the informational masking conditions. HI listeners showed slightly greater performance asymmetry between the low and high CFs than did NH listeners, possibly due to central differences in frequency weighting between groups.

Cortical and Sensory Causes of Individual Differences in Selective Attention Ability Among Listeners With Normal Hearing Thresholds

“…Still, it is clear that the acoustic features that support object formation rely on fine spectral and temporal features of sound, such as harmonic structure, interaural differences, timbre, and other features (Bregman, 1990;Carlyon, 2004;Darwin, 1997). It thus makes sense that listeners with elevated hearing thresholds, who have broader-than-normal cochlear tuning, poor temporal resolution, and reduced dynamic range, will have difficulty communicating in cocktail party settings (e.g., see Best, Mason, & Kidd, 2011;Best, Mason, Kidd, Iyer, & Brungart, 2015;Gallun, Diedesch, Kampel, & Jakien, 2013;Jakien, Kampel, Gordon, & Gallun, 2017;Roverud, Best, Mason, Swaminathan, & Kidd, 2016;Srinivasan, Jakien, & Gallun, 2016; see also the discussion in . However, even listeners with NHTs may differ in the fidelity with which their ears encode acoustic inputs, which may in turn affect their ability to extract auditory objects from a complex acoustic mixture.…”

Hearing-Impaired Listeners Show Reduced Attention to High-Frequency Information in the Presence of Low-Frequency Information

“…Roverud et al (2016) did not directly test the hypothesis that the asymmetries in hearing thresholds contributed to (or were correlated with) the asymmetries in attention across frequency in the HI group. Roverud et al (2016) proposed that the similar performance in selective and divided conditions may have been due to a failure to perceive the content at the two CFs as separate streams during the stimulus presentation (see Shinn-Cunningham & Best, 2008, for a related discussion). As a result, listeners may have always been performing the task by dividing attention-holding both patterns in memory and attempting to perform the selection of the desired pattern after each presentation.…”

“…Counter to expectations, there was no significant difference in performance overall between the selective and divided attention tasks. Roverud et al. (2016) did not directly test the hypothesis that the asymmetries in hearing thresholds contributed to (or were correlated with) the asymmetries in attention across frequency in the HI group.…”

“…Another class of studies has used a different approach that is grounded in masking and, in particular, informational masking (IM; see Kidd et al., 2008 , for a review). In that approach, the ability of NH and HI listeners to selectively attend to content in one frequency region, while ignoring masking content at other frequencies, is examined (e.g., Alexander & Lutfi, 2004 ; de Laat & Plomp, 1985 ; Grose & Hall, 1996 ; Kidd et al., 2001 ; Micheyl et al., 2000 ; Roverud et al., 2016 ). Typically, these studies aim to rule out, or account for, the contributions of peripheral factors to the observed masking effects.…”

“…In a study that forms a precursor to the present investigation, Roverud et al. (2016) examined selective and divided attention to two frequency regions using a pattern identification task.…”