Nicole Marrone

Enhancing Perceptual Learning by Combining Practice with Periods of Additional Sensory Stimulation

Perceptual skills can be improved even in adulthood, but this learning seldom occurs by stimulus exposure alone. Instead, it requires considerable practice performing a perceptual task with relevant stimuli. It is thought that task performance permits the stimuli to drive learning. A corresponding assumption is that the same stimuli do not contribute to improvement when encountered separately from relevant task performance because of the absence of this permissive signal. However, these ideas are based on only two types of studies, in which the task was either always performed or not performed at all. Here we demonstrate enhanced perceptual learning on an auditory frequency-discrimination task in human listeners when practice on that target task was combined with additional stimulation. Learning was enhanced regardless of whether the periods of additional stimulation were interleaved with or provided exclusively before or after target-task performance, and even though that stimulation occurred during the performance of an irrelevant (auditory or written) task. The additional exposures were only beneficial when they shared the same frequency with, though they did not need to be identical to, those used during target-task performance. Their effectiveness also was diminished when they were presented 15 min after practice on the target task and was eliminated when that separation was increased to 4 h. These data show that exposure to an acoustic stimulus can facilitate learning when encountered outside of the time of practice on a perceptual task. By properly using additional stimulation one may markedly improve the efficiency of perceptual training regimens.

Stimulus factors influencing spatial release from speech-on-speech masking

This study examined spatial release from masking (SRM) when a target talker was masked by competing talkers or by other types of sounds. The focus was on the role of interaural time differences (ITDs) and time-varying interaural level differences (ILDs) under conditions varying in the strength of informational masking (IM). In the first experiment, a target talker was masked by two other talkers that were either colocated with the target or were symmetrically spatially separated from the target with the stimuli presented through loudspeakers. The sounds were filtered into different frequency regions to restrict the available interaural cues. The largest SRM occurred for the broadband condition followed by a low-pass condition. However, even the highest frequency bandpass-filtered condition (3-6 kHz) yielded a significant SRM. In the second experiment the stimuli were presented via earphones. The listeners identified the speech of a target talker masked by one or two other talkers or noises when the maskers were colocated with the target or were perceptually separated by ITDs. The results revealed a complex pattern of masking in which the factors affecting performance in colocated and spatially separated conditions are to a large degree independent.

Evaluating the Benefit of Hearing Aids in Solving the Cocktail Party Problem

The benefit of wearing hearing aids in multitalker, reverberant listening environments was evaluated in a study of speech-on-speech masking with two groups of listeners with hearing loss (younger/older). Listeners selectively attended a known spatial location in two room conditions (low/high reverberation) and identified target speech in the presence of two competing talkers that were either colocated or symmetrically spatially separated from the target. The amount of spatial release from masking (SRM) with bilateral aids was similar to that when listening unaided at or near an equivalent sensation level and was negatively correlated with the amount of hearing loss. When using a single aid, SRM was reduced and was related to the level of the stimulus in the unaided ear. Increased reverberation also reduced SRM in all listening conditions. Results suggest a complex interaction between hearing loss, hearing aid use, reverberation, and performance in auditory selective attention tasks.

The influence of non-spatial factors on measures of spatial release from masking

This study tested the hypothesis that the reduction in spatial release from masking (SRM) resulting from sensorineural hearing loss in competing speech mixtures is influenced by the characteristics of the interfering speech. A frontal speech target was presented simultaneously with two intelligible or two time-reversed (unintelligible) speech maskers that were either colocated with the target or were symmetrically separated from the target in the horizontal plane. The difference in SRM between listeners with hearing impairment and listeners with normal hearing was substantially larger for the forward maskers (deficit of 5.8 dB) than for the reversed maskers (deficit of 1.6 dB). This was driven by the fact that all listeners, regardless of hearing abilities, performed similarly (and poorly) in the colocated condition with intelligible maskers. The same conditions were then tested in listeners with normal hearing using headphone stimuli that were degraded by noise vocoding. Reducing the number of available spectral channels systematically reduced the measured SRM, and again, more so for forward (reduction of 3.8 dB) than for reversed speech maskers (reduction of 1.8 dB). The results suggest that non-spatial factors can strongly influence both the magnitude of SRM and the apparent deficit in SRM for listeners with impaired hearing.

Racial/Ethnic and Socioeconomic Disparities in Hearing Health Care Among Older Americans

Objective: Hearing impairment is highly prevalent, but little is known about hearing health care among older minority adults. Method: We analyzed nationally representative, cross-sectional data from 1,544 older adults ≥70 years with audiometry and hearing care data from the 2005-2006 and 2009-2010 National Health and Nutritional Examination Surveys. Results: After adjusting for age and speech frequency pure tone average, Blacks (odds ratio [OR] = 1.68, vs. Whites) and those with greater education (OR = 1.63, ≥college vs. <high school) were more likely to report recent hearing testing, while White older adults and those with greater socioeconomic status were more likely to report regular hearing aid use (all ps < .05). Based on a multivariate analysis, Blacks were not more likely than Whites to use hearing aids despite being more likely to have had recent hearing testing. Discussion: Racial/ethnic and socioeconomic disparities exist in hearing health care and represent critical areas for research and intervention.

Effects of Sensorineural Hearing Loss on Visually Guided Attention in a Multitalker Environment

This study asked whether or not listeners with sensorineural hearing loss have an impaired ability to use top–down attention to enhance speech intelligibility in the presence of interfering talkers. Listeners were presented with a target string of spoken digits embedded in a mixture of five spatially separated speech streams. The benefit of providing simple visual cues indicating when and/or where the target would occur was measured in listeners with hearing loss, listeners with normal hearing, and a control group of listeners with normal hearing who were tested at a lower target-to-masker ratio to equate their baseline (no cue) performance with the hearing-loss group. All groups received robust benefits from the visual cues. The magnitude of the spatial-cue benefit, however, was significantly smaller in listeners with hearing loss. Results suggest that reduced utility of selective attention for resolving competition between simultaneous sounds contributes to the communication difficulties experienced by listeners with hearing loss in everyday listening situations.

Enhancing speech learning by combining task practice with periods of stimulus exposure without practice

Language acquisition typically involves periods when the learner speaks and listens to the new language, and others when the learner is exposed to the language without consciously speaking or listening to it. Adaptation to variants of a native language occurs under similar conditions. Here, speech learning by adults was assessed following a training regimen that mimicked this common situation of language immersion without continuous active language processing. Experiment 1 focused on the acquisition of a novel phonetic category along the voice-onset-time continuum, while Experiment 2 focused on adaptation to foreign-accented speech. The critical training regimens of each experiment involved alternation between periods of practice with the task of phonetic classification (Experiment 1) or sentence recognition (Experiment 2) and periods of stimulus exposure without practice. These practice and exposure periods yielded little to no improvement separately, but alternation between them generated as much or more improvement as did practicing during every period. Practice appears to serve as a catalyst that enables stimulus exposures encountered both during and outside of the practice periods to contribute to quite distinct cases of speech learning. It follows that practice-plus-exposure combinations may tap a general learning mechanism that facilitates language acquisition and speech processing.

The Baltimore HEARS Pilot Study: An Affordable, Accessible, Community-Delivered Hearing Care Intervention

Purpose of the Study Age-related hearing loss negatively affects health outcomes, yet disparities in hearing care, such as hearing aid use, exist based on race/ethnicity and socioeconomic position. Recent national efforts highlight reduction of hearing care disparities as a public health imperative. This study a) describes a community engagement approach to addressing disparities, b) reports preliminary outcomes of a novel intervention, and c) discusses implementation processes and potential for wide-scale testing and use. Design and Methods This was a prospective, randomized control pilot, with a 3-month delayed treatment group as a waitlist control, that assessed feasibility, acceptability, and preliminary efficacy of a community-delivered, affordable, and accessible intervention for older adults with hearing loss. Outcomes were assessed at 3 months, comparing immediate and delayed groups, and pooled to compare the cohorts pre- and 3-month post-intervention results. Results All participants completed the study (n = 15). The program was highly acceptable: 93% benefited, 100% would recommend the program, and 67% wanted to serve as future program trainers. At 3 months, the treated group (n = 8) experienced fewer social and emotional effects of hearing loss and fewer depressive symptoms as compared to the delayed treatment group (n = 7). Pooling 3-month post-intervention scores (n = 15), participants reported fewer negative hearing-related effects (effect size = -0.96) and reduced depressive symptoms (effect size = -0.43). Implications The HEARS (Hearing Equality through Accessible Research & Solutions) intervention is feasible, acceptable, low risk, and demonstrates preliminary efficacy. HEARS offers a novel, low-cost, and readily scalable solution to reduce hearing care disparities and highlights how a community-engaged approach to intervention development can address disparities.

Translation Quality Assessment in Health Research: A Functionalist Alternative to Back-Translation.

As international research studies become more commonplace, the importance of developing multilingual research instruments continues to increase and with it that of translated materials. It is therefore not unexpected that assessing the quality of translated materials (e.g., research instruments, questionnaires, etc.) has become essential to cross-cultural research, given that the reliability and validity of the research findings crucially depend on the translated instruments. In some fields (e.g., public health and medicine), the quality of translated instruments can also impact the effectiveness and success of interventions and public campaigns. Back-translation (BT) is a commonly used quality assessment tool in cross-cultural research. This quality assurance technique consists of (a) translation (target text [TT1]) of the source text (ST), (b) translation (TT2) of TT1 back into the source language, and (c) comparison of TT2 with ST to make sure there are no discrepancies. The accuracy of the BT with respect to the source is supposed to reflect equivalence/accuracy of the TT. This article shows how the use of BT as a translation quality assessment method can have a detrimental effect on a research study and proposes alternatives to BT. One alternative is illustrated on the basis of the translation and quality assessment methods used in a research study on hearing loss carried out in a border community in the southwest of the United States.

Addressing Hearing Health Care Disparities among Older Adults in a US-Mexico Border Community

Hearing loss is associated with cognitive decline and impairment in daily living activities. Access to hearing health care has broad implications for healthy aging of the U.S. population. This qualitative study investigated factors related to the socio-ecological domains of hearing health in a U.S.–Mexico border community experiencing disparities in access to care. A multidisciplinary research team partnered with community health workers (CHWs) from a Federally Qualified Health Center (FQHC) in designing the study. CHWs conducted interviews with people with hearing loss (n = 20) and focus groups with their family/friends (n = 27) and with members of the community-at-large (n = 47). The research team conducted interviews with FQHC providers and staff (n = 12). Individuals experienced depression, sadness, and social isolation, as well as frustration and even anger regarding communication. Family members experienced negative impacts of deteriorating communication, but expressed few coping strategies. There was general agreement across data sources that hearing loss was not routinely addressed within primary care and assistive hearing technology was generally unaffordable. Community members described stigma related to hearing loss and a need for greater access to hearing health care and broader community education. Findings confirm the causal sequence of hearing impairment on quality of life aggravated by socioeconomic conditions and lack of access to hearing health care. Hearing loss requires a comprehensive and innovative public health response across the socio-ecological framework that includes both individual communication intervention and greater access to hearing health resources. CHWs can be effective in tailoring intervention strategies to community characteristics.