Background Speech Disrupts Working Memory Span in 5-Year-Old Children Objectives: The present study tested the effects of background speech and nonspeech noise on 5-year-old children's working memory span. Design: Five-year-old typically developing children (range = 58.6 to 67.6 months; n = 94) completed a modified version of the Missing Scan Task, a missing-item working memory task, in quiet and in the presence of two types of background noise: male two-talker speech and speech-shaped noise. The two types of background noise had similar spectral composition and overall intensity characteristics but differed in whether they contained verbal content. In Experiments 1 and 2, children's memory span (i.e., the largest set size of items children successfully recalled) was subjected to analyses of variance designed to look for an effect of listening condition (within-subjects factor: quiet, background noise) and an effect of background noise type (between-subjects factor: two-talker speech, speech-shaped noise). Results: In Experiment 1, children's memory span declined in the presence of two-talker speech but not in the presence of speech-shaped noise. This result was replicated in Experiment 2 after accounting for a potential effect of proactive interference due to repeated administration of the Missing Scan Task. Conclusions: Background speech, but not speech-shaped noise, disrupted working memory span in 5-year-old children. These results support the idea that background speech engages domain-general cognitive processes used during the recall of known objects in a way that speech-shaped noise does not. | |||||||||||||
Objective Comparison of the Quality and Reliability of Auditory Brainstem Response Features Elicited by Click and Speech Sounds Objectives: Auditory brainstem responses (ABRs) are commonly generated using simple, transient stimuli (e.g., clicks or tone bursts). While resulting waveforms are undeniably valuable clinical tools, they are unlikely to be representative of responses to more complex, behaviorally relevant sounds such as speech. There has been interest in the use of more complex stimuli to elicit the ABR, with considerable work focusing on the use of synthetically generated consonant–vowel (CV) stimuli. Such responses may be sensitive to a range of clinical conditions and to the effects of auditory training. Several ABR features have been documented in response to CV stimuli; however, an important issue is how robust such features are. In the current research, we use time- and frequency-domain objective measures of quality to compare the reliability of Wave V of the click-evoked ABR to that of waves elicited by the CV stimulus /da/. Design: Stimuli were presented to 16 subjects at 70 dB nHL in quiet for 6000 epochs. The presence and quality of response features across subjects were examined using Fsp and a Bootstrap analysis method, which was used to assign p values to ABR features for individual recordings in both time and frequency domains. Results: All consistent peaks identified within the /da/-evoked response had significantly lower amplitude than Wave V of the ABR. The morphology of speech-evoked waveforms varied across subjects. Mean Fsp values for several waves of the speech-evoked ABR were below 3, suggesting low quality. The most robust response to the /da/ stimulus appeared to be an offset response. Only click-evoked Wave V showed 100% wave presence. Responses to the /da/ stimulus showed lower wave detectability. Frequency-domain analysis showed stronger and more consistent activity evoked by clicks than by /da/. Only the click ABR had consistent time–frequency domain features across all subjects. Conclusions: Based on the objective analysis used within this investigation, it appears that the quality of speech-evoked ABR is generally less than that of click-evoked responses, although the quality of responses may be improved by increasing the number of epochs or the stimulation level. This may have implications for the clinical use of speech-evoked ABR. | |||||||||||||
Working Memory and Extended High-Frequency Hearing in Adults: Diagnostic Predictors of Speech-in-Noise Perception Objective: The purpose of this study was to identify the main factors that differentiate listeners with clinically normal or "near-normal" hearing with regard to their speech-in-noise perception and to develop a regression model to predict speech-in-noise difficulties in this population. We also aimed to assess the potential effectiveness of the formula produced by the regression model as a "diagnostic criterion" for clinical use. Design: Data from a large-scale behavioral study investigating the relationship between noise exposure and auditory processing in 122 adults (30 to 57 years) was re-examined. For each participant, a composite speech-in-noise score (CSS) was calculated based on scores from three speech-in-noise measures, (a) the Speech, Spatial and Qualities of Hearing scale (average of speech items); (b) the Listening in Spatialized Noise Sentences test (high-cue condition); and (c) the National Acoustic Laboratories Dynamic Conversations Test. Two subgroups were created based on the CSS, each comprising 30 participants: those with the lowest scores and those with the highest scores. These two groups were compared for differences in hearing thresholds, temporal perception, noise exposure, attention, and working memory. They differed significantly on age, low-, high-, and extended high-frequency (EHF) hearing level, sensitivity to temporal fine structure and amplitude modulation, linguistic closure skills, attention, and working memory. A multiple linear regression model was fit with these nine variables as predictors to determine their relative effect on the CSS. The two significant predictors, EHF hearing and working memory, from this regression were then used to fit a second smaller regression model. The resulting regression formula was assessed for its usefulness as a "diagnostic criterion" for predicting speech-in-noise difficulties using Monte Carlo cross-validation (root mean square error and area under the receiver operating characteristics curve methods) in the complete data set. Results: EHF hearing thresholds (p = 0.01) and working memory scores (p < 0.001) were significant predictors of the CSS and the regression model accounted for 41% of the total variance [R2 = 0.41, F(9,112) = 7.57, p < 0.001]. The overall accuracy of the diagnostic criterion for predicting the CSS and for identifying "low" CSS performance, using these two factors, was reasonable (area under the receiver operating characteristics curve = 0.76; root mean square error = 0.60). Conclusions: These findings suggest that both peripheral (auditory) and central (cognitive) factors contribute to the speech-in-noise difficulties reported by normal hearing adults in their mid-adult years. The demonstrated utility of the diagnostic criterion proposed here suggests that audiologists should include assessment of EHF hearing and working memory as part of routine clinical practice with this population. The "diagnostic criterion" we developed based on these two factors could form the basis of future clinical tests and rehabilitation tools and be used in evidence-based counseling for normal hearers who present with unexplained communication difficulties in noise. | |||||||||||||
Time From Hearing Aid Candidacy to Hearing Aid Adoption: A Longitudinal Cohort Study Objectives: Although many individuals with hearing loss could benefit from intervention with hearing aids, many do not seek or delay seeking timely treatment after the onset of hearing loss. There is limited data-based evidence estimating the delay in adoption of hearing aids with anecdotal estimates ranging from 5 to 20 years. The present longitudinal study is the first to assess time from hearing aid candidacy to adoption in a 28-year ongoing prospective cohort of older adults, with the additional goal of determining factors influencing delays in hearing aid adoption, and self-reported successful use of hearing aids. Design: As part of a longitudinal study of age-related hearing loss, a wide range of demographic, biologic, and auditory measures are obtained yearly or every 2 to 3 years from a large sample of adults, along with family, medical, hearing, noise exposure, and hearing aid use histories. From all eligible participants (age ≥18; N = 1530), 857 were identified as hearing aid candidates either at baseline or during their participation, using audiometric criteria. Longitudinal data were used to track transition to hearing aid candidacy and hearing aid adoption. Demographic and hearing-related characteristics were compared between hearing aid adopters and nonadopters. Unadjusted estimated overall time (in years) to hearing aid adoption and estimated delay times were stratified by demographic and hearing-related factors and were determined using a time-to-event analysis (survival analysis). Factors influencing rate of adoption in any given time period were examined along with factors influencing successful hearing aid adoption. Results: Age, number of chronic health conditions, sex, retirement status, and education level did not differ significantly between hearing aid adopters and nonadopters. In contrast, adopters were more likely than nonadopters to be married, of white race, have higher socioeconomic status, have significantly poorer higher frequency (2.0, 3.0, 4.0, 6.0, and 8.0 kHz) pure-tone averages, poorer word recognition in quiet and competing multi-talker babble, and reported more hearing handicap on the Hearing Handicap Inventory for the Elderly/Adults emotional and social subscales. Unadjusted estimation of time from hearing aid candidacy to adoption in the full participant cohort was 8.9 years (SE ± 0.37; interquartile range = 3.2–14.9 years) with statistically significant stratification for race, hearing as measured by low- and high-frequency pure-tone averages, keyword recognition in low-context sentences in babble, and the Hearing Handicap Inventory for the Elderly/Adults social score. In a subgroup analysis of the 213 individuals who adopted hearing aids and were assigned a success classification, 78.4% were successful. No significant predictors of success were found. Conclusions: The average delay in adopting hearing aids after hearing aid candidacy was 8.9 years. Nonwhite race and better speech recognition (in a more difficult task) significantly increased the delay to treatment. Poorer hearing and more self-assessed hearing handicap in social situations significantly decreased the delay to treatment. These results confirm the assumption that adults with hearing loss significantly delay seeking treatment with hearing aids. | |||||||||||||
Voice Emotion Recognition by Children With Mild-to-Moderate Hearing Loss Objectives: Emotional communication is important in children's social development. Previous studies have shown deficits in voice emotion recognition by children with moderate-to-severe hearing loss or with cochlear implants. Little, however, is known about emotion recognition in children with mild-to-moderate hearing loss. The objective of this study was to compare voice emotion recognition by children with mild-to-moderate hearing loss relative to their peers with normal hearing, under conditions in which the emotional prosody was either more or less exaggerated (child-directed or adult-directed speech, respectively). We hypothesized that the performance of children with mild-to-moderate hearing loss would be comparable to their normally hearing peers when tested with child-directed materials but would show significant deficits in emotion recognition when tested with adult-directed materials, which have reduced prosodic cues. Design: Nineteen school-aged children (8 to 14 years of age) with mild-to-moderate hearing loss and 20 children with normal hearing aged 6 to 17 years participated in the study. A group of 11 young, normally hearing adults was also tested. Stimuli comprised sentences spoken in one of five emotions (angry, happy, sad, neutral, and scared), either in a child-directed or in an adult-directed manner. The task was a single-interval, five-alternative forced-choice paradigm, in which the participants heard each sentence in turn and indicated which of the five emotions was associated with that sentence. Reaction time was also recorded as a measure of cognitive load. Results: Acoustic analyses confirmed the exaggerated prosodic cues in the child-directed materials relative to the adult-directed materials. Results showed significant effects of age, specific emotion (happy, sad, etc.), and test materials (better performance with child-directed materials) in both groups of children, as well as susceptibility to talker variability. Contrary to our hypothesis, no significant differences were observed between the 2 groups of children in either emotion recognition (percent correct or d' values) or in reaction time, with either child- or adult-directed materials. Among children with hearing loss, degree of hearing loss (mild or moderate) did not predict performance. In children with hearing loss, interactions between vocabulary, materials, and age were observed, such that older children with stronger vocabulary showed better performance with child-directed speech. Such interactions were not observed in children with normal hearing. The pattern of results was broadly consistent across the different measures of accuracy, d', and reaction time. Conclusions: Children with mild-to-moderate hearing loss do not have significant deficits in overall voice emotion recognition compared with their normally hearing peers, but mechanisms involved may be different between the 2 groups. The results suggest a stronger role for linguistic ability in emotion recognition by children with normal hearing than by children with hearing loss. | |||||||||||||
Is There a Safe Level for Recording Vestibular Evoked Myogenic Potential? Evidence From Cochlear and Hearing Function Tests Objective: There is a growing concern among the scientific community about the possible detrimental effects of signal levels used for eliciting vestibular evoked myogenic potentials (VEMPs) on hearing. A few recent studies showed temporary reduction in amplitude of otoacoustic emissions (OAE) after VEMP administration. Nonetheless, these studies used higher stimulus levels (133 and 130 dB peak equivalent sound pressure level [pe SPL]) than the ones often used (120 to 125 dB pe SPL) for clinical recording of VEMP. Therefore, it is not known whether these lower levels also have similar detrimental impact on hearing function. Hence, the present study aimed at investigating the effect of 500 Hz tone burst presented at 125 dB pe SPL on hearing functions. Design: True experimental design, with an experimental and a control group, was used in this study. The study included 60 individuals with normal auditory and vestibular system. Of them, 30 underwent unilateral VEMP recording (group I) while the remaining 30 did not undergo VEMP testing (group II). Selection of participants to the groups was random. Pre- and post-VEMP assessments included pure-tone audiometry (250 to 16,000 Hz), distortion product OAE, and subjective symptoms. To simulate the time taken for VEMP testing in group I, participants in group II underwent these tests twice with a gap of 15 minutes. Results: No participant experienced any subjective symptom after VEMP testing. There was no significant interear and intergroup difference in pure-tone thresholds and distortion product OAE amplitude before and after VEMP recording (p > 0.05). Furthermore, the response rate of cervical VEMP was 100% at stimulus intensity of 125 dB pe SPL. Conclusions: Use of 500 Hz tone burst at 125 dB pe SPL does not cause any temporary or permanent changes in cochlear function and hearing, yet produces 100% response rate of cervical VEMP in normal-hearing young adults. Therefore, 125 dB pe SPL of 500 Hz tone burst is recommended as safe level for obtaining cervical VEMP without significantly losing out on its response rate, at least in normal-hearing young adults. | |||||||||||||
Bimodal Hearing or Bilateral Cochlear Implants? Ask the Patient Objective: The objectives of this study were to assess the effectiveness of various measures of speech understanding in distinguishing performance differences between adult bimodal and bilateral cochlear implant (CI) recipients and to provide a preliminary evidence-based tool guiding clinical decisions regarding bilateral CI candidacy. Design: This study used a multiple-baseline, cross-sectional design investigating speech recognition performance for 85 experienced adult CI recipients (49 bimodal, 36 bilateral). Speech recognition was assessed in a standard clinical test environment with a single loudspeaker using the minimum speech test battery for adult CI recipients as well as with an R-SPACETM 8-loudspeaker, sound-simulation system. All participants were tested in three listening conditions for each measure including each ear alone as well as in the bilateral/bimodal condition. In addition, we asked each bimodal listener to provide a yes/no answer to the question, "Do you think you need a second CI?" Results: This study yielded three primary findings: (1) there were no significant differences between bimodal and bilateral CI performance or binaural summation on clinical measures of speech recognition, (2) an adaptive speech recognition task in the R-SPACETM system revealed significant differences in performance and binaural summation between bimodal and bilateral CI users, with bilateral CI users achieving significantly better performance and greater summation, and (3) the patient's answer to the question, "Do you think you need a second CI?" held high sensitivity (100% hit rate) for identifying likely bilateral CI candidates and moderately high specificity (77% correct rejection rate) for correctly identifying listeners best suited with a bimodal hearing configuration. Conclusions: Clinics cannot rely on current clinical measures of speech understanding, with a single loudspeaker, to determine bilateral CI candidacy for adult bimodal listeners nor to accurately document bilateral benefit relative to a previous bimodal hearing configuration. Speech recognition in a complex listening environment, such as R-SPACETM, is a sensitive and appropriate measure for determining bilateral CI candidacy and also likely for documenting bilateral benefit relative to a previous bimodal configuration. In the absence of an available R-SPACETM system, asking the patient whether or not s/he thinks s/he needs a second CI is a highly sensitive measure, which may prove clinically useful. | |||||||||||||
Effects of Early Auditory Deprivation on Working Memory and Reasoning Abilities in Verbal and Visuospatial Domains for Pediatric Cochlear Implant Recipients Objectives: The overall goal of this study was to compare verbal and visuospatial working memory in children with normal hearing (NH) and with cochlear implants (CI). The main questions addressed by this study were (1) Does auditory deprivation result in global or domain-specific deficits in working memory in children with CIs compared with their NH age mates? (2) Does the potential for verbal recoding affect performance on measures of reasoning ability in children with CIs relative to their NH age mates? and (3) Is performance on verbal and visuospatial working memory tasks related to spoken receptive language level achieved by children with CIs? Design: A total of 54 children ranging in age from 5 to 9 years participated; 25 children with CIs and 29 children with NH. Participants were tested on both simple and complex measures of verbal and visuospatial working memory. Vocabulary was assessed with the Peabody Picture Vocabulary Test (PPVT) and reasoning abilities with two subtests of the WISC-IV (Wechsler Intelligence Scale for Children, 4th edition): Picture Concepts (verbally mediated) and Matrix Reasoning (visuospatial task). Groups were compared on all measures using analysis of variance after controlling for age and maternal education. Results: Children with CIs scored significantly lower than children with NH on measures of working memory, after accounting for age and maternal education. Differences between the groups were more apparent for verbal working memory compared with visuospatial working memory. For reasoning and vocabulary, the CI group scored significantly lower than the NH group for PPVT and WISC Picture Concepts but similar to NH age mates on WISC Matrix Reasoning. Conclusions: Results from this study suggest that children with CIs have deficits in working memory related to storing and processing verbal information in working memory. These deficits extend to receptive vocabulary and verbal reasoning and remain even after controlling for the higher maternal education level of the NH group. Their ability to store and process visuospatial information in working memory and complete reasoning tasks that minimize verbal labeling of stimuli more closely approaches performance of NH age mates. | |||||||||||||
Music Appreciation of Adult Hearing Aid Users and the Impact of Different Levels of Hearing Loss Objectives: The main aim of this study was to collect information on music listening and music appreciation from postlingually deafened adults who use hearing aids (HAs). It also sought to investigate whether there were any differences in music ratings from HA users with different levels of hearing loss (HL; mild, versus moderate to moderately-severe, versus severe or worse. Design: An existing published questionnaire developed for cochlear implant recipients was modified for this study. It had 51 questions divided into seven sections: (1) music listening and music background; (2) sound quality; (3) musical styles; (4) music preferences; (5) music recognition; (6) factors affecting music listening enjoyment; and (7) music training program. The questionnaire was posted out to adult HA users, who were subsequently divided into three groups: (i) HA users with a mild HL (Mild group); (ii) HA users with a moderate to moderately-severe HL (Moderate group); and (iii) HA users with a severe or worse (Severe group) HL. Results: One hundred eleven questionnaires were completed; of these, 51 participants had a mild HL, 42 had a moderate to moderately-severe loss, and 18 a severe or worse loss. Overall, there were some significant differences noted, predominantly between the Mild and Severe groups, with fewer differences between the Mild and Moderate groups. The respondents with the greater levels of HL reported a greater reduction in their music enjoyment as a result of their HL and that HAs made music sound significantly less melodic for them. It was also observed that the Severe group's mean scores for both the pleasant rating as well as the combined rating for the six different musical styles were lower than both the Mild and Moderate groups' ratings for every style, with just one exception (pop/rock pleasantness rating). There were significant differences between the three groups for the styles of music that were reported to sound the best with HA(s), as well as differences between the ratings on more specific timbre rating scales used to rate different elements of each style. In rating the pleasantness and naturalness of different musical instruments or instrumental groups, there was no difference between the groups. There were also significant differences between the Mild and Severe groups in relation to musical preferences for the pitch range of music, with the Severe group significantly preferring male singers and lower pitched instruments. Conclusions: The overall results indicated little difference in music appreciation between those with a mild versus moderate loss. However, poorer appreciation scores were given by those with a severe or worse HL. This would suggest that HAs or HL have a negative impact on music listening, particularly when the HL becomes more significant. There was a large degree of variability in ratings, though, with music listening being satisfactory for some listeners and largely unsatisfactory for others, in all three groups. Music listening preferences also varied significantly, and the reported benefit (or otherwise) provided by the HA for music was also mixed. The overriding variability in listening preferences and ratings leads to the question as to the benefit and effectiveness of generic, manufacturer-derived music programs on HAs. Despite the heterogeneity in the listening habits, preferences, and ratings, it is clear that music appreciation and enjoyment is still challenging for many HA users and that level of HL is one, but not the only factor that impacts on music appreciation. | |||||||||||||
Redundant Information Is Sometimes More Beneficial Than Spatial Information to Understand Speech in Noise Objectives: To establish a framework to unambiguously define and relate the different spatial effects in speech understanding: head shadow, redundancy, squelch, spatial release from masking (SRM), and so on. Next, to investigate the contribution of interaural time and level differences to these spatial effects in speech understanding and how this is influenced by the type of masking noise. Design: In our framework, SRM is uniquely characterized as a linear combination of head shadow, binaural redundancy, and binaural squelch. The latter two terms are combined into one binaural term, which we define as binaural contrast: a benefit of interaural differences. In this way, SRM is a simple sum of a monaural and a binaural term. We used the framework to quantify these spatial effects in 10 listeners with normal hearing. The participants performed speech intelligibility tasks in different spatial setups. We used head-related transfer functions to manipulate the presence of interaural time and level differences. We used three spectrally matched masker types: stationary speech-weighted noise, a competing talker, and speech-weighted noise that was modulated with the broadband temporal envelope of the competing talker. Results: We found that (1) binaural contrast was increased by interaural time differences, but reduced by interaural level differences, irrespective of masker type, and (2) large redundancy (the benefit of having identical information in two ears) could reduce binaural contrast and thus also reduce SRM. Conclusions: Our framework yielded new insights in binaural processing in speech intelligibility. First, interaural level differences disturb speech intelligibility in realistic listening conditions. Therefore, to optimize speech intelligibility in hearing aids, it is more beneficial to improve monaural signal-to-noise ratios rather than to preserve interaural level differences. Second, although redundancy is mostly ignored when considering spatial hearing, it might explain reduced SRM in some cases.
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Alexandros Sfakianakis
Anapafseos 5 . Agios Nikolaos
Crete.Greece.72100
2841026182
Anapafseos 5 . Agios Nikolaos
Crete.Greece.72100
2841026182
6948891480
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