Aging and Speech-on-Speech Masking

Abstract

Objectives-A common complaint of many older adults is difficulty communicating in situations where they must focus on one talker in the presence of other people speaking. In listening environments containing multiple talkers, age-related changes may be caused by increased sensitivity to energetic masking, increased susceptibility to informational masking (e.g., confusion between the target voice and masking voices), and/or cognitive deficits. The purpose of the present study was to tease out these contributions to the difficulties that older adults experience in speech-on-speech masking situations.Design-Groups of younger, normal-hearing individuals and older adults with varying degrees of hearing sensitivity (n = 12 per group) participated in a study of sentence recognition in the presence of four types of maskers: a two-talker masker consisting of voices of the same sex as the target voice, a two-talker masker of voices of the opposite sex as the target, a signal-envelope-modulated noise derived from the two-talker complex, and a speech-shaped steady noise. Subjects also completed a voice discrimination task to determine the extent to which they were able to incidentally learn to tell apart the target voice from the same-sex masking voices and to examine whether this ability influenced speech-on-speech masking.Results-Results showed that older adults had significantly poorer performance in the presence of all four types of maskers, with the largest absolute difference for the same-sex masking condition. When the data were analyzed in terms of relative group differences (i.e., adjusting for absolute performance) the greatest effect was found for the opposite-sex masker. Degree of hearing loss was significantly related to performance in several listening conditions. Some older subjects demonstrated a reduced ability to discriminate between the masking and target voices; performance on this task was not related to speech recognition ability.Conclusions-The overall pattern of results suggests that although amount of informational masking does not seem to differ between older and younger listeners, older adults (particularly those with hearing loss) evidence a deficit in the ability to selectively attend to a target voice, even when the masking voices are from talkers of the opposite sex. Possible explanations for these findings include problems understanding speech in the presence of a masker with temporal and spectral fluctuations and/or age-related changes in cognitive function.The primary auditory complaint of many older people is difficulty understanding speech in noisy situations. Numerous studies have documented this age-related decline in the ability to comprehend speech in the presence of a masker (e.g., Dubno, Dirks, & Shaefer, 1987;Plomp & Mimpen 1979). This research has demonstrated that older adults with presbycusis generally have greater difficulty understanding masked speech than do young, normal-hearing individuals. Although a portion of this problem is because of the filtering and distortio...

Development of attentional control of verbal auditory perception from middle to late childhood: Comparisons to healthy aging.

“…Thus far, little is known about differences or similarities in the underlying mechanisms of attentional control of auditory perception between child development and healthy aging. Older adults' deficits in auditory processing relative to younger adults likely reflect effects of compromised sensory functions that are further augmented by agingrelated attentional deficits (e.g., Helfer & Freyman, 2008;Tun, O'Kane, & Wingfield, 2002). In contrast, agerelated improvements in dichotic listening performance from middle to late childhood are likely to primarily or exclusively reflect age-graded changes in attentional control (Hugdahl et al, 2001;Ridderinkhof et al, 1997;Rueda et al, 2004;Takio et al, 2009;Waszak et al, 2010), given that basic auditory mechanisms reach adultlike levels in early childhood (e.g., Stalinski et al, 2008;Trehub et al, 1988;Werner, 1996).…”

Human aging compromises attentional control of auditory perception.

“…In line with previous studies of younger adults (Tallus et al, 2007;Westerhausen et al, 2009), we expected the effect of attentional focus on the REA to vary systematically with the degree of competition between perceptual saliency and attentional focus. However, given age-related declines in auditory attention (e.g., Helfer & Freyman, 2008;Sommers & Danielson, 1999), we hypothesized that older adults' performance would be less regulated by attention and, instead, would be more driven by perceptual saliency. This effect would be reflected in smaller deviations of the REA under focused attention relative to the neutral-focus conditions in older adults as compared with younger adults.…”

“…Put differently, age-related declines in peripheral and central auditory processing necessitate more attentional control during auditory processing (see GordonSalant et al, 2010). However, a prominent aspect of cognitive aging is attentional deficit and increased susceptibility to distractions across a broad range of visual tasks (e.g., Spieler, Balota, & Faust, 1996;Whiting, Madden, & Babcock, 2007) and auditory tasks (e.g., Helfer & Freyman, 2008;Sommers & Danielson, 1999).…”

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

“…Aging can also impede spatial selective auditory attention (e.g., Snell et al 2002;Tun et al 2002;Helfer and Freyman 2008;Marrone et al 2008a, b;Singh et al 2008). Anecdotally, even middle-aged listeners report problems with selective auditory attention (Helfer and Freyman 2008;Wambacq et al 2009).…”