The one-up one-down adaptive (staircase) procedure in speech-in-noise testing: Standard error of measurement and fluctuations in the track.

The one-up one-down adaptive (staircase or up-down) procedure is often used to estimate the speech recognition threshold (SRT) in speech-in-noise testing. This article provides a brief historical overview of the one-up one-down procedure in psychophysics, discussing the groundbreaking early work that is still relevant to clinical audiology and scientific research. Next, this article focuses on two aspects of the one-up one-down adaptive procedure: first, the standard error of measurement (SEM) and, second, the fluctuations in the track [i.e., the standard deviation of the signal-to-noise ratios of the stimuli within the track (SDtrack)]. Simulations of ideal and non-ideal listeners and experimental data are used to determine and evaluate different relationships between the parameters slope of the speech recognition function, SRT, SEM, and SDtrack. Hearing loss and non-ideal behavior (inattentiveness, fatigue, and giving up when the task becomes too difficult) slightly increase the average value of SDtrack. SDtrack, however, poorly discriminates between reliable and unreliable SRT estimates.

Lexical-Access Ability and Cognitive Predictors of Speech Recognition in Noise in Adult Cochlear Implant Users.

Not all of the variance in speech-recognition performance of cochlear implant (CI) users can be explained by biographic and auditory factors. In normal-hearing listeners, linguistic and cognitive factors determine most of speech-in-noise performance. The current study explored specifically the influence of visually measured lexical-access ability compared with other cognitive factors on speech recognition of 24 postlingually deafened CI users. Speech-recognition performance was measured with monosyllables in quiet (consonant-vowel-consonant [CVC]), sentences-in-noise (SIN), and digit-triplets in noise (DIN). In addition to a composite variable of lexical-access ability (LA), measured with a lexical-decision test (LDT) and word-naming task, vocabulary size, working-memory capacity (Reading Span test [RSpan]), and a visual analogue of the SIN test (text reception threshold test) were measured. The DIN test was used to correct for auditory factors in SIN thresholds by taking the difference between SIN and DIN: SRTdiff. Correlation analyses revealed that duration of hearing loss (dHL) was related to SIN thresholds. Better working-memory capacity was related to SIN and SRTdiff scores. LDT reaction time was positively correlated with SRTdiff scores. No significant relationships were found for CVC or DIN scores with the predictor variables. Regression analyses showed that together with dHL, RSpan explained 55% of the variance in SIN thresholds. When controlling for auditory performance, LA, LDT, and RSpan separately explained, together with dHL, respectively 37%, 36%, and 46% of the variance in SRTdiff outcome. The results suggest that poor verbal working-memory capacity and to a lesser extent poor lexical-access ability limit speech-recognition ability in listeners with a CI.

Morphosyntactic correctness of written language production in adults with moderate to severe congenital hearing loss.

OBJECTIVE: To examine whether moderate to severe congenital hearing loss (MSCHL) leads to persistent morphosyntactic problems in the written language production of adults, as it does in their spoken language production. DESIGN: Samples of written language in Dutch were analysed for morphosyntactic correctness and syntactic complexity. STUDY SAMPLE: 20 adults with MSCHL and 10 adults with normal hearing (NH). RESULTS: Adults with MSCHL did not differ from adults with NH in the morphosyntactic correctness and syntactic complexity of their written utterances. Within the MSCHL group, the number of morphosyntactic errors in writing was related to the degree of hearing loss in childhood. CONCLUSIONS: At the group level, MSCHL does not affect the morphosyntactic correctness of language produced in the written modality, in contrast to earlier observed effects on spoken language production. However, at the individual level, our data suggest that adults who acquired their language with more severe auditory limitations are more at risk of persistent problems with morphosyntax in written language production than adults with a lower degree of hearing loss in childhood.

Change in Psychosocial Health Status Over 5 Years in Relation to Adults' Hearing Ability in Noise.

OBJECTIVES: The aim of this study was to establish the longitudinal relationship between hearing ability in noise and psychosocial health outcomes (i.e., loneliness, anxiety, depression, distress, and somatization) in adults aged 18 to 70 years. An additional objective was to determine whether a change in hearing ability in noise over a period of 5 years was associated with a change in psychosocial functioning. Subgroup effects for a range of factors were investigated. DESIGN: Longitudinal data of the web-based Netherlands Longitudinal Study on Hearing (NL-SH) (N = 508) were analyzed. The ability to recognize speech in noise (i.e., the speech-reception-threshold [SRTn]) was measured with an online digit triplet test at baseline and at 5-year follow-up. Psychosocial health status was assessed by online questionnaires. Multiple linear regression analyses and longitudinal statistical analyses (i.e., generalized estimating equations) were performed. RESULTS: Poorer SRTn was associated longitudinally with more feelings of emotional and social loneliness. For participants with a high educational level, the longitudinal association between SRTn and social loneliness was significant. Changes in hearing ability and loneliness appeared significantly associated only for specific subgroups: those with stable pattern of hearing aid nonuse (increased emotional and social loneliness), who entered matrimony (increased social loneliness), and low educational level (less emotional loneliness). No significant longitudinal associations were found between hearing ability and anxiety, depression, distress, or somatization. CONCLUSIONS: Hearing ability in noise was longitudinally associated with loneliness. Decline in hearing ability in noise was related to increase in loneliness for specific subgroups of participants. One of these subgroups included participants whose hearing deteriorated over 5 years, but who continued to report nonuse of hearing aids. This is an important and alarming finding that needs further investigation.

The Influence of Linguistic Proficiency on Masked Text Recognition Performance in Adults With and Without Congenital Hearing Impairment.

OBJECTIVE: The authors first examined the influence of moderate to severe congenital hearing impairment (CHI) on the correctness of samples of elicited spoken language. Then, the authors used this measure as an indicator of linguistic proficiency and examined its effect on performance in language reception, independent of bottom-up auditory processing. DESIGN: In groups of adults with normal hearing (NH, n = 22), acquired hearing impairment (AHI, n = 22), and moderate to severe CHI (n = 21), the authors assessed linguistic proficiency by analyzing the morphosyntactic correctness of their spoken language production. Language reception skills were examined with a task for masked sentence recognition in the visual domain (text), at a readability level of 50%, using grammatically correct sentences and sentences with distorted morphosyntactic cues. The actual performance on the tasks was compared between groups. RESULTS: Adults with CHI made more morphosyntactic errors in spoken language production than adults with NH, while no differences were observed between the AHI and NH group. This outcome pattern sustained when comparisons were restricted to subgroups of AHI and CHI adults, matched for current auditory speech reception abilities. The data yielded no differences between groups in performance in masked text recognition of grammatically correct sentences in a test condition in which subjects could fully take advantage of their linguistic knowledge. Also, no difference between groups was found in the sensitivity to morphosyntactic distortions when processing short masked sentences, presented visually. CONCLUSIONS: These data showed that problems with the correct use of specific morphosyntactic knowledge in spoken language production are a long-term effect of moderate to severe CHI, independent of current auditory processing abilities. However, moderate to severe CHI generally does not impede performance in masked language reception in the visual modality, as measured in this study with short, degraded sentences. Aspects of linguistic proficiency that are affected by CHI thus do not seem to play a role in masked sentence recognition in the visual modality.

The influence of lexical-access ability and vocabulary knowledge on measures of speech recognition in noise.

OBJECTIVE: The main objective was to investigate the effect of linguistic abilities (lexical-access ability and vocabulary size) on different measures of speech-in-noise recognition in normal-hearing listeners with various levels of language proficiency. DESIGN: Speech reception thresholds (SRTs) were measured for sentences in steady-state (SRTstat) and fluctuating noise (SRTfluc), and for digit-triplets in steady-state noise (DIN). Lexical-access ability was measured with a lexical-decision test and a word-naming test. Vocabulary size was also measured. For the SRT, keyword scoring and sentence scoring were compared. STUDY SAMPLE: To introduce variation in linguistic abilities, three groups of 24 young normal-hearing listeners were included: higher-educated native, lower-educated native, and higher-educated non-native listeners. RESULTS: Lexical-access ability was most accurately measured with combined results of lexical decision and word naming. Lexical-access ability explained 60% of the variance in SRT. The effect of linguistic abilities on SRTs was up to 5.6 dB for SRTstat and 8 dB for SRTfluc. Using keyword scoring reduced this effect by approximately 1.5 dB. For DIN the effect of linguistic ability was less than 1 dB. CONCLUSIONS: Lexical-access ability is an important predictor of SRTs in normal-hearing listeners. These results are important to consider in the interpretation of speech-in-noise scores of hearing-impaired listeners.

Medication Use in Adults with and without Hearing Impairment.

The objective of this study was to determine whether hearing ability in adults is associated with medication use in general, the use of specific types of medication, or polypharmacy. In this exploratory study, data of the National Longitudinal Study on Hearing (NL-SH; n = 2,160) were used. In total, 62% of the participants reported using any medication in the past 28 days. Hearing ability in noise, as determined with an online digit-triplet speech-in-noise test, was significantly associated with (1) medication acting on the alimentary tract and metabolism (including diabetes and acid-related disorders), (2) use of calcium blockers, and (3) medication used for sensory organs.

Deterioration of Speech Recognition Ability Over a Period of 5 Years in Adults Ages 18 to 70 Years: Results of the Dutch Online Speech-in-Noise Test.

OBJECTIVES: The first aim of the present study was to determine the change in speech recognition in noise over a period of 5 years in participants ages 18 to 70 years at baseline. The second aim was to investigate whether age, gender, educational level, the level of initial speech recognition in noise, and reported chronic conditions were associated with a change in speech recognition in noise. DESIGN: The baseline and 5-year follow-up data of 427 participants with and without hearing impairment participating in the National Longitudinal Study on Hearing (NL-SH) were analyzed. The ability to recognize speech in noise was measured twice with the online National Hearing Test, a digit-triplet speech-in-noise test. Speech-reception-threshold in noise (SRTn) scores were calculated, corresponding to 50% speech intelligibility. Unaided SRTn scores obtained with the same transducer (headphones or loudspeakers) at both test moments were included. Changes in SRTn were calculated as a raw shift (T1 - T0) and an adjusted shift for regression towards the mean. Paired t tests and multivariable linear regression analyses were applied. RESULTS: The mean increase (i.e., deterioration) in SRTn was 0.38-dB signal-to-noise ratio (SNR) over 5 years (p < 0.001). Results of the multivariable regression analyses showed that the age group of 50 to 59 years had a significantly larger deterioration in SRTn compared with the age group of 18 to 39 years (raw shift: beta: 0.64-dB SNR; 95% confidence interval: 0.07-1.22; p = 0.028, adjusted for initial speech recognition level - adjusted shift: beta: 0.82-dB SNR; 95% confidence interval: 0.27-1.34; p = 0.004). Gender, educational level, and the number of chronic conditions were not associated with a change in SRTn over time. No significant differences in increase of SRTn were found between the initial levels of speech recognition (i.e., good, insufficient, or poor) when taking into account the phenomenon regression towards the mean. CONCLUSIONS: The study results indicate that hearing deterioration of speech recognition in noise over 5 years can also be detected in adults ages 18 to 70 years. This rather small numeric change might represent a relevant impact on an individual's ability to understand speech in everyday life.

Assessing speech recognition abilities with digits in noise in cochlear implant and hearing aid users.

OBJECTIVE: The primary objective of the study was to investigate the feasibility, reliability, and validity of the Dutch digits in noise (DIN) test for measuring speech recognition in hearing aid and cochlear implant users and compare results to the standard sentences-in-noise (SIN) test. DESIGN: The relation between speech reception thresholds for DIN test and SIN test was analysed to determine the validity of the DIN test. As linguistic skills were expected to make different contributions in these tests, their influence was analysed. STUDY SAMPLE: Participants were 12 normal-hearing listeners, 24 hearing aid users, and 24 cochlear implant users. RESULTS: The DIN test was feasible for more participants than the SIN test. Intraclass correlation coefficients showed high reliability. The standard error of measurement was smaller for the DIN test than for the SIN test. DIN test and SIN test were highly correlated (r = 0.95 and r = 0.56 for NH+ HA and CI users respectively). In the regression analysis no significant contribution of basic linguistic skills or personal factors was found. CONCLUSION: In the assessment of speech recognition in noise of aided hearing-impaired listeners with hearing aids or cochlear implants, the DIN test is a feasible, reliable and valid test.

Speech-in-speech listening on the LiSN-S test by older adults with good audiograms depends on cognition and hearing acuity at high frequencies.

OBJECTIVES: The main objective was to investigate age-related differences on the listening in spatialized noise-sentences (LiSN-S) test in adults with normal audiometric thresholds in most of the speech range. A second objective was to examine the contributions of auditory, cognitive, and linguistic abilities to LiSN-S outcomes. DESIGN: The LiSN-S test was administered to participants in an older group (M(Age) = 72.0, SD = 4.3 years) and a younger group (M(Age) = 21.7, SD = 2.6 years) with N = 26 per group. All the participants had clinically normal audiometric thresholds at frequencies up to and including 3000 Hz. The LiSN-S test yields a speech reception threshold (SRT) in each of the four speech-in-speech listening conditions that differ in the availability of voice difference cues and/or spatial separation cues. Based on these four SRTs, the scores were calculated for the talker advantage, the spatial advantage, and the total advantage as a result of both the types of cues. Additionally, the participants completed four auditory temporal-processing tests, a cognitive screening test, a vocabulary test, and tests of linguistic closure for high- and low-context sentences. The contributions of these predictor variables and measures of pure-tone hearing acuity to LiSN-S outcomes were analyzed for both the groups using regression analyses. RESULTS: Younger listeners outperformed the older listeners on all four LiSN-S SRTs and all the three LiSN-S advantage measures. Age-related differences were larger for conditions involving the use of spatial cues. For the younger group, all LiSN-S SRTs were predicted by the measure of linguistic closure in low-context sentences; in addition, the SRT for the condition with voice difference cues but without spatial separation cues was predicted by vocabulary, and the SRT for the condition with both voice difference cues and spatial separation cues was predicted by temporal resolution at low frequencies. Vocabulary also contributed to the talker advantage in the younger group, whereas the spatial advantage was predicted by high-frequency pure-tone hearing acuity in the range 6,000 to 10,000 Hz (pure-tone average [PTA](HIGH)). For the older group, the LiSN-S SRT in the condition with neither voice difference cues nor spatial separation cues was predicted by age; their other three LiSN-S SRTs and all advantage measures were predicted by PTA(HIGH). In addition, for the older group, cognition predicted LiSN-S SRT outcomes in three of the four conditions. Measures of auditory temporal processing, linguistic abilities, or hearing acuity up to and including 4000 Hz did not predict LiSN-S outcomes in this group. CONCLUSIONS: LiSN-S outcomes were poorer for adults aged 65 years or older, even those with good audiograms, compared with younger adults and also compared with people up to the age of 60 years from a previous study. In the present study, regardless of the types of cues, auditory and cognitive interactions were reflected by the combined influences on LiSN-S outcomes of high-frequency hearing acuity and measures of linguistic and cognitive processing. The data also suggest a hierarchy in the deployment of processing resources, which would account for the observed shift from linguistic abilities in the younger group to general cognitive abilities in the older group.

Hearing Loss in Older Persons: Does the Rate of Decline Affect Psychosocial Health?

OBJECTIVE: This study investigates whether the rate of decline in older persons' hearing status is associated with the rate of decrease in their psychosocial health and explores moderation by baseline hearing status, health-related factors, and sociodemographic factors. METHOD: Multilevel analyses were applied to data of 1,178 older participants from the Longitudinal Aging Study Amsterdam (LASA), covering 3 to 7 years of follow-up. RESULTS: Faster decrease in speech-in-noise recognition was significantly associated with more increase in loneliness for persons with a moderate baseline speech-in-noise recognition (emotional and social loneliness) and for persons who recently lost their partner (emotional loneliness). No relationship was found with depression. DISCUSSION: The results indicate that faster hearing decline results in more increase in loneliness in specific subgroups of older persons: in persons with an already impaired hearing and in widow(er)s. Monitoring older persons' hearing seems important and may be a relevant starting point for targeted loneliness prevention efforts.

The influence of informational masking on speech perception and pupil response in adults with hearing impairment.

A recent pupillometry study on adults with normal hearing indicates that the pupil response during speech perception (cognitive processing load) is strongly affected by the type of speech masker. The current study extends these results by recording the pupil response in 32 participants with hearing impairment (mean age 59 yr) while they were listening to sentences masked by fluctuating noise or a single-talker. Efforts were made to improve audibility of all sounds by means of spectral shaping. Additionally, participants performed tests measuring verbal working memory capacity, inhibition of interfering information in working memory, and linguistic closure. The results showed worse speech reception thresholds for speech masked by single-talker speech compared to fluctuating noise. In line with previous results for participants with normal hearing, the pupil response was larger when listening to speech masked by a single-talker compared to fluctuating noise. Regression analysis revealed that larger working memory capacity and better inhibition of interfering information related to better speech reception thresholds, but these variables did not account for inter-individual differences in the pupil response. In conclusion, people with hearing impairment show more cognitive load during speech processing when there is interfering speech compared to fluctuating noise.

Comorbidity in adults with hearing difficulties: which chronic medical conditions are related to hearing impairment?

OBJECTIVES: To investigate the occurrence of 27 chronic medical conditions in a cohort of adults with and without hearing impairment, and to examine the association between these conditions and hearing ability. DESIGN: The National Longitudinal Study on Hearing (NL-SH study) is a large prospective study among adults aged 18 to 70 years, conducted via the internet in the Netherlands. Hearing ability was measured with a digits-in-noise test and comorbidity was assessed through self-report. STUDY SAMPLE: Cross-sectional data of 890 hearing-impaired and 975 normally-hearing adults were analyzed. Both descriptive statistics and multinomial logistic regression analyses were conducted. RESULTS: Of the NL-SH participants with insufficient or poor hearing ability, 78.5% reported to suffer from at least one additional chronic condition. This proportion was larger than in the normally-hearing group (68.6% with one or more chronic conditions and 37.7% with two or more). After adjustment for age and gender, 'dizziness causing falling', 'diabetes' and 'arthritis types other than osteoarthritis and rheumatic arthritis' were significantly associated with poor hearing ability. CONCLUSIONS: Our results show that some previously reported associations do not only occur in older age groups, but also in younger cohorts. Comorbidity is relevant in the rehabilitation (multi-disciplinary care) and the clinical encounter.

Dual sensory loss: A major age-related increase of comorbid hearing loss and hearing aid ownership in visually impaired adults.

AIM: Despite increasing interest in visual and hearing impairment in the older population, little attention has been paid to concurrent hearing and vision loss, also known as dual sensory loss. The aim of the present study was to investigate the prevalence of comorbid hearing disability and hearing aid ownership in visually impaired older adults. METHODS: In a cross-sectional survey, a self-report hearing disability screener was administered to 1396 visually impaired patients (aged ≥ 50 years) of outpatient low vision rehabilitation centers in the Netherlands and Belgium. RESULTS: Of all participants, 44.8% (95% CI 42.2-47.5) had insufficient or poor hearing; the prevalence increased quadratically with age. Of all dual sensory impaired participants, 31.2% in the Netherlands and 55.7% in Belgium did not own hearing aids. CONCLUSIONS: The high prevalence of dual sensory loss calls for more awareness of related problems in these patients. Differences between the Netherlands and Belgium regarding hearing aid ownership might be due to different criteria used for hearing aid referral and insurance policies. For patients with dual sensory loss, specialized care implemented in low vision rehabilitation seems warranted.

Decline in older persons' ability to recognize speech in noise: the influence of demographic, health-related, environmental, and cognitive factors.

OBJECTIVES: The first aim was to investigate whether the rate of decline in older persons' ability to recognize speech in noise over time differs across age and gender. The second aim was to determine extent demographic, health-related, environmental, and cognitive factors influence the change in speech-in-noise recognition over time. DESIGN: Data covering 3 to 7 years of follow-up (mean: 4.9 years) of a large sample of the Longitudinal Aging Study Amsterdam were used (n = 1298; 3025 observations; baseline ages: 57 to 93 years). Hearing ability was measured by a digit triplet speech-in-noise test (SNT) yielding a speech reception threshold in noise (SRTn). Multilevel analyses were used to model the change in SRTn over time. First, interaction terms were used to test differences in rate of decline across subgroups. Second, for each of the following factors the authors determined the influence on the change in SRTn: age, gender, educational level, cardiovascular conditions, information processing speed, fluid intelligence, global cognitive functioning, smoking, and alcohol use. This was done by calculating the percentage change in Btime after adding the particular factor to the model. RESULTS: On average, respondents' SRTn increased (i.e., deteriorated) significantly over time by 0.18 dB signal-to-noise ratio per annum. Rates were accelerated for older ages (Btime = 0.13, 0.14, 0.25, 0.27 for persons who were 57 to 65, 65 to 75, 75 to 85, and 85 to 93 years of age, respectively). Only information processing speed relevantly influenced the change in SRTn over time (17% decrease in Btime). CONCLUSIONS: Decline in older persons' speech-in-noise recognition over time accelerated for older ages. Decline in information processing speed explained a moderate proportion of the SRTn decline. This indicates the relevance of declining cognitive abilities in the ability of older persons to recognize speech in noisy environments.

Vocational rehabilitation services for people with hearing difficulties: a systematic review of the literature.

OBJECTIVE: The goal of this review was to list and summarize work-related health programs for employees with hearing difficulties and to summarize the statistical evidence of the effectiveness of these programs. METHODS: A systematic review was performed by searching the PubMed, EMBASE, PsycINFO, CINAHL, and The Cochrane Library databases for relevant citations. From 2313 unique citations retrieved from the search strategy, we included nine programs that met all inclusion criteria. The authors assessed the methodological quality of studies which evaluated the program's effectiveness, using the Downs and Black checklist. RESULTS: Nine vocational rehabilitation programs for people with hearing difficulties were described. The programs differed in procedure, duration, setting, and content. In four studies, the effectiveness of the program was explored statistically. Measurements showed an improvement in general health (SF-36), communication strategies, and the degree of work readiness, but none of these studies included a control group, a power calculation, nor adjusted for confounding. Hence, the methodological quality to provide evidence of effectiveness was assessed as poor. DISCUSSION: Existing vocational programs for employees with hearing difficulties provide relevant information to demonstrate how to implement the appropriate content of the programs. Future research is required to improve the strength of evidence of the effectiveness of vocational rehabilitation for workers with hearing difficulties.

Dual sensory loss: development of a dual sensory loss protocol and design of a randomized controlled trial.

BACKGROUND: Dual sensory loss (DSL) has a negative impact on health and wellbeing and its prevalence is expected to increase due to demographic aging. However, specialized care or rehabilitation programs for DSL are scarce. Until now, low vision rehabilitation does not sufficiently target concurrent impairments in vision and hearing. This study aims to 1) develop a DSL protocol (for occupational therapists working in low vision rehabilitation) which focuses on optimal use of the senses and teaches DSL patients and their communication partners to use effective communication strategies, and 2) describe the multicenter parallel randomized controlled trial (RCT) designed to test the effectiveness and cost-effectiveness of the DSL protocol. METHODS/DESIGN: To develop a DSL protocol, literature was reviewed and content was discussed with professionals in eye/ear care (interviews/focus groups) and DSL patients (interviews). A pilot study was conducted to test and confirm the DSL protocol. In addition, a two-armed international multi-center RCT will evaluate the effectiveness and cost-effectiveness of the DSL protocol compared to waiting list controls, in 124 patients in low vision rehabilitation centers in the Netherlands and Belgium. DISCUSSION: This study provides a treatment protocol for rehabilitation of DSL within low vision rehabilitation, which aims to be a valuable addition to the general low vision rehabilitation care. TRIAL REGISTRATION: Netherlands Trial Register (NTR) identifier: NTR2843.

How linguistic closure and verbal working memory relate to speech recognition in noise--a review.

The ability to recognize masked speech, commonly measured with a speech reception threshold (SRT) test, is associated with cognitive processing abilities. Two cognitive factors frequently assessed in speech recognition research are the capacity of working memory (WM), measured by means of a reading span (Rspan) or listening span (Lspan) test, and the ability to read masked text (linguistic closure), measured by the text reception threshold (TRT). The current article provides a review of recent hearing research that examined the relationship of TRT and WM span to SRTs in various maskers. Furthermore, modality differences in WM capacity assessed with the Rspan compared to the Lspan test were examined and related to speech recognition abilities in an experimental study with young adults with normal hearing (NH). Span scores were strongly associated with each other, but were higher in the auditory modality. The results of the reviewed studies suggest that TRT and WM span are related to each other, but differ in their relationships with SRT performance. In NH adults of middle age or older, both TRT and Rspan were associated with SRTs in speech maskers, whereas TRT better predicted speech recognition in fluctuating nonspeech maskers. The associations with SRTs in steady-state noise were inconclusive for both measures. WM span was positively related to benefit from contextual information in speech recognition, but better TRTs related to less interference from unrelated cues. Data for individuals with impaired hearing are limited, but larger WM span seems to give a general advantage in various listening situations.

Task difficulty differentially affects two measures of processing load: the pupil response during sentence processing and delayed cued recall of the sentences.

PURPOSE: In this study, the authors assessed the influence of masking level (29% or 71% sentence perception) and test modality on the processing load during language perception as reflected by the pupil response. In addition, the authors administered a delayed cued stimulus recall test to examine whether processing load affected the encoding of the stimuli in memory. METHOD: Participants performed speech and text reception threshold tests, during which the pupil response was measured. In the cued recall test, the first half of correctly perceived sentences was presented, and participants were asked to complete the sentences. Reading and listening span tests of working memory capacity were presented as well. RESULTS: Regardless of test modality, the pupil response indicated higher processing load in the 29% condition than in the 71% correct condition. Cued recall was better for the 29% condition. CONCLUSIONS: The consistent effect of masking level on the pupil response during listening and reading support the validity of the pupil response as a measure of processing load during language perception. The absent relation between pupil response and cued recall may suggest that cued recall is not directly related to processing load, as reflected by the pupil response.

The interpretation of speech reception threshold data in normal-hearing and hearing-impaired listeners: II. Fluctuating noise.

Following previous work [Smits and Festen. (2011). J. Acoust. Soc. Am. 130, 2987-2998] involving the interpretation of speech reception threshold (SRT) data in steady-state noise, the present study considers fluctuating noise. Whereas the SIIsteady function [i.e., the speech intelligibility index (SII) against SNR in steady-state noise] can be approximated by a simple linear function going from 0 to 1 between SNR = -15 dB to +15 dB, the SIIfluc function is a function over a broader range than 30 dB and its maximum lies at a SNR higher than +15 dB. The difference in shape between the SIIsteady and SIIfluc functions has several implications. It predicts a reduction in fluctuating masker benefit (FMB), or even a negative FMB, for higher SNRs for normal-hearing listeners. Experimental data confirm this prediction. Much of the reduction in FMB for hearing-impaired listeners may be attributed to the higher SRTs in steady-state noise for these listeners.