Hearing Age Research Articles

Normative data for assessing performance on a rapid, automated test of speech-on-speech masking and spatial release from masking

The ability to understand speech in the presence of competing sound sources is essential to communication success. This task is difficult for listeners with healthy auditory systems, but becomes substantially more difficult as listeners age and experience various insults to the system. Our laboratory has developed a rapid, automated method of measuring the relative ability to perform a standard laboratory version of this task, which has been applied to a large set of spatial separations between 0 and 135 degrees, and a range of levels and bandwidths. Performance has been obtained in over 100 listeners varying in age and hearing ability between one and fifteen times over the course of four years. We have examined both the reliability of this test, by comparing how performance changed across test sessions with the same acoustical conditions (less than 1 dB on average), and the relative influences of age and hearing loss at various separations. Normative functions based on over 100 listeners are available for a colocated control condition, a spatial separation of 45 degrees, and the difference between the two (spatial release from masking). Normative functions take into account both age, between 18 and 80 years, and moderate hearing loss in the standard audiometric frequencies. A calibrated version of the test is freely available for use on an iPad.

Interlocutor accommodation on the variation of /tɾ/ in Chilean radio

This study examines linguistic and extra-linguistic factors that motivate the production of the affricated variant [tʃ] of the consonant cluster/tɾ/, as in otro ‘other’ produced as [o.tʃɾo], in Chilean Spanish, with a focus on the effect of speech accommodation. This study presents the results of a mixed-effects logistic regression analysis and two-population binomial tests that together expose multiple factors affecting /tɾ/ cluster variation in this speech community. Results of this study show that the sex and age of the immediate listeners influence variant selection, thus reinforcing the need for speech accommodation analyses in sociolinguistic research. This study updates the literature on Chilean /tɾ/ variation for middle and upper class speakers using a large dataset of professional public speech, suggesting that the affricated variant is also gaining linguistic prestige.

Effect of Dysarthria Type, Speaking Condition, and Listener Age on Speech Intelligibility.

The aim of this study was to examine the effect of loud and slow speech cues on younger and older listeners' comprehension of dysarthric speech, specifically, (a) whether one strategy, as opposed to the other, promoted greater intelligibility gains for different speaker groups; (b) whether older and younger listeners' understandings were differentially affected by these strategies; and (c) which acoustic changes best predicted intelligibility gain in individual speakers. Twenty younger and 40 older listeners completed a perceptual task. Six individuals with dysarthria produced phrases across habitual, loud, and slow conditions. The primary dependent variable was proportion of words correct; follow-up acoustic analyses linked perceptual outcomes to changes in acoustic speech features. Regardless of dysarthria type, the loud condition produced significant intelligibility gains. Overall, older listeners' comprehension was reduced relative to younger listeners. Follow-up analysis revealed considerable interspeaker differences in intelligibility outcomes across conditions. Although the most successful speaking mode varied, intelligibility gains were strongly associated with the degree of change participants made to their vowel formants. Perceptual outcomes vary across speaking modes, even when speakers with dysarthria are grouped according to similar perceptual profiles. Further investigation of interspeaker differences is needed to inform individually tailored intervention approaches.

Romance, Exemplum, and the Subject of the Confessio Amantis

Romance, Exemplum, and the Subject ofthe Confessio Amantis William Robins University ofToronto T,ve,s;on of the story of Apollon;u, of Tyre that John Gowe, presents in book 8 of the Confessio Amantis is an ancient romance con­ strued according to the expectations for an exemplum.1 Many of the other medieval adaptations of this ancient romance may have been "ex­ emplary" in a wide sense ofthat term, referring in a loose fashion to any stories that were presented so as to engage the reader morally. Gower's version, however, is the first to be couched in the more precisely defined structure of an exemplum, such as was developed in late thirteenth­ century sermons and thence introduced into fourteenth-century narra­ tives as a device for linking a story to a specific moral argument.2 Employed as one element in a sermon or moral treatise, an exemplum bears both a narrative and a rhetorical burden: through a narrative em­ plotment it must present a particular case of the operation of some abstract vice or virtue, while at the same time it is also meant to warn A slightly different version of this paper originally appeared in my "Ancient Romance and Medieval Literary Genres: Apollonius of Tyre" (Ph.D. diss., Princeton University, 1995), pp. 167-200. I wish to thank John V. Fleming, Robert Hollander, Seth Lerer, Thomas Pavel, and the members of the Seminar on Contemporary Critical Theory at Princeton for their comments and advice. 1 Citations of the Confessio Amantis are by book and line number from John Gower, Confessio Amantis, ed. G. C. Macaulay, vols. 2-3 of The Complete Works ofJohn Gower (Oxford: Clarendon Press, 1899-1902). 2 "This is the first version . . . in which the story is presented explicitly as a moral ex­ emplum, albeit in a style which owes much to romance conventions"; Elizabeth Archibald, Apollonius ofTyre: Medieval and Renaissance Themes and Variations (Cambridge: D. S. Brewer, 1991), p. 192. On the history of the Historia Apollonii Regis Tyri and its adaptations see Archibald, Apollonius ofTyre; G. A. A. Korrekaas, ed., Historia Apollonii Regis Tyri (Groningen: Brouma's Boekhuis, 1984); and Elimar Klebs, Die Erzahlung von Apollonius aus Tyrus: eine geschichtliche Untersuchung iiber ihre lateinischen Urform und ihre spciteren Bearbeitungen (Berlin: G. Reimer, 1889). On the history of the exemplum, the standard work remains J.-Th. Welter, L'Exemplum dans la litterature religieuse et didactique du moyen age (Paris: Guitard, 1927). 157 STUDIES IN THE AGE OF CHAUCER listeners from, or exhort them to, a course ofbehavior through the moral­ isatio following a tale. Gower's "Tale of Apollonius" has such a moralisa­ tio and is set within a larger exemplary framework, yet there is a strik­ ing dissonance between the emplotment inherited from this ancient romance and the moral attached to it. For a reader who might be determined to find a moral in every story, the moralisatio of this tale will seem no more exceptionable than other tenuously linked conclusions common in medieval literature, and might appear, as it does to A. J. Minnis, "obvious."3 But for a reader mindful of the way an exemplum ought to match its narrative and ex­ hortatory purposes ("solum quodfacit ad rem est narrandum"4), as is gen­ erally the case in the other tales ofthe ConfessioAmantis, the relation be­ tween this romance and its proffered moral seems, as it does to Charles Runacres, "uninformative and confusing."5 Dramatically opposed strat­ egies of reading, according to which this moralization of ancient ro­ mance can appear as obvious or as confusing, are already present within Gower's poem, voiced respectively by the teller, Genius, and the lis­ tener, Amans. This opposition, I will argue, produces the conditions by which ancient romance becomes a tool with which Gower can investi­ gate the nature ofexemplarity, both in the "Tale of Apollonius" and in the Confessio Amantis as a whole. I will claim that the goal of Gower's strategy to contrast romance and exemplum is to prompt his readers to recognize their situation at the intersection of two discursive modes, a situation which I will describe, in the terms of recent theories of sub­ jectivity, as the...

Gap Detection in School-Age Children and Adults: Center Frequency and Ramp Duration.

The age at which gap detection becomes adultlike differs, depending on the stimulus characteristics. The present study evaluated whether the developmental trajectory differs as a function of stimulus frequency region or duration of the onset and offset ramps bounding the gap. Thresholds were obtained for wideband noise (500-4500 Hz) with 4- or 40-ms raised-cosine ramps and for a 25-Hz-wide low-fluctuation narrowband noise centered on either 500 or 5000 Hz with 40-ms ramps. Stimuli were played continuously at 70 dB SPL, and the task was to indicate which of 3 intervals contained a gap. Listeners were 5.2- to 15.1-year-old children (n = 40) and adults (n = 10) with normal hearing. Regardless of listener age, gap detection thresholds for the wideband noise tended to be lower when gaps were shaped using 4-ms rather than 40-ms ramps. Thresholds also tended to be lower for the low-fluctuation narrowband noise centered on 5000 Hz than 500 Hz. Performance reached adult levels after 11 years of age for all 4 stimuli. Maturation was not uniform across individuals, however; a subset of young children performed like adults, including some 5-year-olds. For these stimuli, the developmental trajectory was similar regardless of narrowband noise center frequency or wideband noise onset and offset ramp duration.

Effect of response context and masker type on word recognition in school-age children and adults.

In adults, masked speech recognition improves with the provision of a closed set of response alternatives. The present study evaluated whether school-age children (5-13 years) benefit to the same extent as adults from a forced-choice context, and whether this effect depends on masker type. Experiment 1 compared masked speech reception thresholds for disyllabic words in either an open-set or a four-alternative forced-choice (4AFC) task. Maskers were speech-shaped noise or two-talker speech. Experiment 2 compared masked speech reception thresholds for monosyllabic words in two 4AFC tasks, one in which the target and foils were phonetically similar and one in which they were dissimilar. Maskers were speech-shaped noise, amplitude-modulated noise, or two-talker speech. For both experiments, it was predicted that children would not benefit from the information provided by the 4AFC context to the same degree as adults, particularly when the masker was complex (two-talker) or when audible speech cues were temporally sparse (modulated-noise). Results indicate that young children do benefit from a 4AFC context to the same extent as adults in speech-shaped noise and amplitude-modulated noise, but the benefit of context increases with listener age for the two-talker speech masker.

Effects of age on speech and voice quality ratings.

The quality of communication may be affected by listeners' perception of talkers' characteristics. This study examined if there were effects of talker and listener age on the perception of speech and voice qualities. Younger and older listeners judged younger and older talkers' gender and age, then rated speech samples on pleasantness, naturalness, clarity, ease of understanding, loudness, and the talker's suitability to be an audiobook reader. For the same talkers, listeners also rated voice samples on pleasantness, roughness, and power. Younger and older talkers were perceived to be similar on most qualities except age. Younger and older listeners rated talkers similarly, except that younger listeners perceived younger voices to be more pleasant and less rough than older voices. For vowel samples, younger listeners were more accurate than older listeners at age estimation, while older listeners were more accurate than younger listeners at gender identification, suggesting that younger and older listeners differ in their evaluation of specific talker characteristics. Thus, the perception of quality was generally more affected by the age of the listener than the age of the talker, and age-related differences between listeners depended on whether voice or speech samples were used and the rating being made.

Tales from the dip: Factors in cross-rate intelligibility variation of interrupted speech

Speech intelligibility involves integration of temporally and spectrally distributed acoustic information into higher-order perceptual categories to obtain individual words. In 1950, Miller and Licklider pioneered a simple but powerful method of interrupting speech that has been extensively used to investigate factors that make speech signals perceptually robust. Among numerous subsequent studies, a consistent finding has been a nonmonotonic relationship between intelligibility and interruption rate. As interruption rate increases, and the duration of speech fragments in each interruption cycle decreases, a U-shaped rate-intelligibility function with a dip around 1–5 Hz frequently emerges. While many factors (e.g., speech materials, task parameters, listener age, or hearing status) have been shown to influence performance at specific interruption rates, reasons for the appearance and location of the dip in the function have remained obscure. Previous work indicates that the location of the dip in the rate...

Perception of voice onset time in Singapore English

This study investigates how voice onset time (VOT) is perceived in Singapore English (SgE). SgE research acknowledges that Singaporeans linguistically accommodate their listeners—varying between using Standard Singapore English (SSE) or Singlish (colloquial SgE) depending on addressee. Liu 2011 (n.p.) suggests these linguistic accommodations are reflected in VOT production, finding Singaporeans to produce more short-lag VOT (indicative of Singlish) when speaking to other Singaporeans and longer VOT (indicative of SSE) when speaking to Americans. Though these are sub-categorical shifts, they demonstrate the utility of VOT in speakers’ efforts when accommodating listeners. The current study tests whether VOT is also available as a salient and social perceptual cue. Three listening experiments investigate (1) Singaporeans’ baseline categorical perception of a /ba/-/pa/ continuum, (2) whether this baseline is affected when heard with socially salient pictures (i.e., linguistic stereotypes—an ah lian or a business woman), and (3) whether dialectal carrier phrases—whether stimuli are presented within a SSE or Singlish phrase—affects perception of the same stimuli. Preliminary results show listener age and educational background, which allude to an effect of dialectal experience (Sumner and Samuel 2009), play important roles in the perception of VOT.

Aging and Spectro-Temporal Integration of Speech.

The purpose of this study was to determine the effects of age on the spectro-temporal integration of speech. The hypothesis was that the integration of speech fragments distributed over frequency, time, and ear of presentation is reduced in older listeners—even for those with good audiometric hearing. Younger, middle-aged, and older listeners (10 per group) with good audiometric hearing participated. They were each tested under seven conditions that encompassed combinations of spectral, temporal, and binaural integration. Sentences were filtered into two bands centered at 500 Hz and 2500 Hz, with criterion bandwidth tailored for each participant. In some conditions, the speech bands were individually square wave interrupted at a rate of 10 Hz. Configurations of uninterrupted, synchronously interrupted, and asynchronously interrupted frequency bands were constructed that constituted speech fragments distributed across frequency, time, and ear of presentation. The over-arching finding was that, for most configurations, performance was not differentially affected by listener age. Although speech intelligibility varied across condition, there was no evidence of performance deficits in older listeners in any condition. This study indicates that age, per se, does not necessarily undermine the ability to integrate fragments of speech dispersed across frequency and time.

Suprathreshold auditory processing deficits in noise: Effects of hearing loss and age

People with sensorineural hearing loss generally suffer from a reduced ability to understand speech in complex acoustic listening situations, particularly when background noise is present. In addition to the loss of audibility, a mixture of suprathreshold processing deficits is possibly involved, like altered basilar membrane compression and related changes, as well as a reduced ability of temporal coding. A series of 6 monaural psychoacoustic experiments at 0.5, 2, and 6 kHz was conducted with 18 subjects, divided equally into groups of young normal-hearing, older normal-hearing and older hearing-impaired listeners, aiming at disentangling the effects of age and hearing loss on psychoacoustic performance in noise. Random frequency modulation detection thresholds (RFMDTs) with a low-rate modulator in wide-band noise, and discrimination of a phase-jittered Schroeder-phase from a random-phase harmonic tone complex are suggested to characterize the individual ability of temporal processing. The outcome was compared to thresholds of pure tones and narrow-band noise, loudness growth functions, auditory filter bandwidths, and tone-in-noise detection thresholds. At 500 Hz, results suggest a contribution of temporal fine structure (TFS) to pure-tone detection thresholds. Significant correlation with auditory thresholds and filter bandwidths indicated an impact of frequency selectivity on TFS usability in wide-band noise. When controlling for the effect of threshold sensitivity, the listener's age significantly correlated with tone-in-noise detection and RFMDTs in noise at 500 Hz, showing that older listeners were particularly affected by background noise at low carrier frequencies.

Adults, but not children, benefit from a pretrial signal cue in a random-frequency, two-tone masker.

This study examined the benefit of a pretrial cue, a preview of the signal, on children's (5-10 years) and adults' detection of a 1000-Hz pure-tone signal in a broadband noise or a random-frequency, two-tone masker. No cuing effect was observed with the noise masker, regardless of listener age. In contrast, all but one adult benefited from the cue with the two-tone masker (average = 9.4 dB). Most children showed no cuing effect (average = 0.1 dB) with the two-tone masker. These results suggest that, unlike adults, the provision of a pretrial cue does not promote frequency-selective listening during detection for 5- to 10-year-olds.

Speech Performance and Training Effects in the Cochlear Implant Elderly

Objectives: Cochlear implantation requires acclimatization to the electrical input. Usually, cochlear implant (CI) listeners undergo an auditory rehabilitation program that includes auditory training sessions. Recently, it was shown that a phoneme-based training may improve speech perception abilities even in experienced CI listeners. The current study focuses on whether the effect of an auditory training program depends on the age of CI listeners. Design: Fifteen CI listeners took part in an auditory phoneme-based computer training program. Before and after training, speech recognition tests in moderate and difficult noise (+5 dB SNR and 0 dB SNR, respectively) were administered. Additionally, speech recognition was tested 6 months after the training (follow-up). A control group consisting of 12 subjects underwent audiometric testing without any auditory training. Results: Speech perception in moderate noise improved significantly during the training as revealed by comparing pre- and posttraining scores evaluated in the moderate noise condition. No significant change was observed for the difficult noise situation at 0 dB SNR. The speech perception measures of the control group remained unchanged. No significant effect of age on the training effect was observed. Conclusion: Speech recognition can be improved even in experienced CI listeners. When motivated to participate, senior CI users with long-term CI experience may benefit in a similar way from an auditory, phoneme-based computer training program as younger CI users.

Noun plural production in preschoolers with early cochlear implantation: An experimental study of Dutch and German

ObjectivesStudies investigating language skills of children after cochlear implantation usually present general measures of expressive/receptive vocabulary and grammar and rarely tackle the acquisition of specific language phenomena (word classes, grammatical constructions, word forms, etc.). Furthermore, research is largely restricted to children acquiring English. Cross-linguistic comparisons among children acquiring different languages are almost inexistent. The present study targets the acquisition of noun plurals (e.g., dogs, balls) by Dutch- and German-speaking children implanted before their second birthday. Given its structural complexity and irregularity, noun plural formation is a good indicator of grammatical proficiency in children at risk for a developmental delay. MethodsThe study sample consisted of 14 cochlear-implanted (CI) children (M=55 months of age), 80 age-matched normally hearing (NH) controls, and 40 normally hearing controls matched by Hearing Age (HA). The children were administered an elicitation task in which they had to provide plural forms to a set of singular nouns. The analysis focussed on the following variables: Hearing status (CI, NH), Language (Dutch, German), and Suffix Predictability/Stem Transparency of the plural words. ResultsThere was no significant difference between children with CI and their NH peers in correct plural production. In both child groups, plural responses followed the predicted pattern of Suffix Predictability/Stem Transparency. However, children with CI significantly more frequently replied to the test item with a recast of the singular noun instead of the plural, and the probability of these responses increased with later age of CI implantation. Furthermore, Dutch-speaking children showed an overall better performance than German-speaking children. ConclusionsThe findings suggest that after 3 years of implant use, preschoolers with early cochlear implantation show age-appropriate patterns of noun plural formation, but still have to catch up with respect to associating a particular singular with its plural form.

Effects of masker type, sentence context, and listener age on speech recognition performance in 1-back listening tasks.

Studies have shown that older listeners with normal hearing have greater difficulty understanding speech in noisy environments than younger listeners even during simple assessments where listeners respond to auditory stimuli immediately after presentation. Older listeners may have increased difficulty understanding speech in challenging listening situations that require the recall of prior sentences during the presentation of new auditory stimuli. This study compared the performance of older and younger normal-hearing listeners in 0-back trials, which required listeners to respond to the most recent sentence, and 1-back trials, which required the recall of the sentence preceding the most recent. Speech stimuli were high-context and anomalous sentences with four types of maskers. The results show that older listeners have greater difficulty in the 1-back task than younger listeners with all masker types, even when SNR was adjusted to produce 80% correct performance in the 0-back task for both groups. The differences between the groups in the 1-back task may be explained by differences in working memory for the noise and spatially separated speech maskers but not in the conditions with co-located speech maskers, suggesting that older listeners have increased difficulty in memory-intensive speech perception tasks involving high levels of informational masking.

Gap detection and temporal modulation transfer function as behavioral estimates of auditory temporal acuity using band-limited stimuli in young and older adults.

Gap detection and the temporal modulation transfer function (TMTF) are 2 common methods to obtain behavioral estimates of auditory temporal acuity. However, the agreement between the 2 measures is not clear. This study compares results from these 2 methods and their dependencies on listener age and hearing status. Gap detection thresholds and the parameters that describe the TMTF (sensitivity and cutoff frequency) were estimated for young and older listeners who were naive to the experimental tasks. Stimuli were 800-Hz-wide noises with upper frequency limits of 2400 Hz, presented at 85 dB SPL. A 2-track procedure (Shen & Richards, 2013) was used for the efficient estimation of the TMTF. No significant correlation was found between gap detection threshold and the sensitivity or the cutoff frequency of the TMTF. No significant effect of age and hearing loss on either the gap detection threshold or the TMTF cutoff frequency was found, while the TMTF sensitivity improved with increasing hearing threshold and worsened with increasing age. Estimates of temporal acuity using gap detection and TMTF paradigms do not seem to provide a consistent description of the effects of listener age and hearing status on temporal envelope processing.

Intelligibility of emotional speech in younger and older adults.

Little is known about the influence of vocal emotions on speech understanding. Word recognition accuracy for stimuli spoken to portray seven emotions (anger, disgust, fear, sadness, neutral, happiness, and pleasant surprise) was tested in younger and older listeners. Emotions were presented in either mixed (heterogeneous emotions mixed in a list) or blocked (homogeneous emotion blocked in a list) conditions. Three main hypotheses were tested. First, vocal emotion affects word recognition accuracy; specifically, portrayals of fear enhance word recognition accuracy because listeners orient to threatening information and/or distinctive acoustical cues such as high pitch mean and variation. Second, older listeners recognize words less accurately than younger listeners, but the effects of different emotions on intelligibility are similar across age groups. Third, blocking emotions in list results in better word recognition accuracy, especially for older listeners, and reduces the effect of emotion on intelligibility because as listeners develop expectations about vocal emotion, the allocation of processing resources can shift from emotional to lexical processing. Emotion was the within-subjects variable: all participants heard speech stimuli consisting of a carrier phrase followed by a target word spoken by either a younger or an older talker, with an equal number of stimuli portraying each of seven vocal emotions. The speech was presented in multi-talker babble at signal to noise ratios adjusted for each talker and each listener age group. Listener age (younger, older), condition (mixed, blocked), and talker (younger, older) were the main between-subjects variables. Fifty-six students (Mage= 18.3 years) were recruited from an undergraduate psychology course; 56 older adults (Mage= 72.3 years) were recruited from a volunteer pool. All participants had clinically normal pure-tone audiometric thresholds at frequencies ≤3000 Hz. There were significant main effects of emotion, listener age group, and condition on the accuracy of word recognition in noise. Stimuli spoken in a fearful voice were the most intelligible, while those spoken in a sad voice were the least intelligible. Overall, word recognition accuracy was poorer for older than younger adults, but there was no main effect of talker, and the pattern of the effects of different emotions on intelligibility did not differ significantly across age groups. Acoustical analyses helped elucidate the effect of emotion and some intertalker differences. Finally, all participants performed better when emotions were blocked. For both groups, performance improved over repeated presentations of each emotion in both blocked and mixed conditions. These results are the first to demonstrate a relationship between vocal emotion and word recognition accuracy in noise for younger and older listeners. In particular, the enhancement of intelligibility by emotion is greatest for words spoken to portray fear and presented heterogeneously with other emotions. Fear may have a specialized role in orienting attention to words heard in noise. This finding may be an auditory counterpart to the enhanced detection of threat information in visual displays. The effect of vocal emotion on word recognition accuracy is preserved in older listeners with good audiograms and both age groups benefit from blocking and the repetition of emotions.

Variables that influence the recognition performance of interrupted words: rise-fall shape and temporal location of the interruptions.

The abrupt transition of a signal from off to on and vice versa typically produces spectral splatter that can mask other signals that are spectrally removed from the nominal signal frequency. Both the Miller and Licklider (1950) and Cherry (1953) studies of interrupted speech and alternated speech, respectively, acknowledged the generation of extraneous noise by the rapid on and off characteristics of their unshaped signals but noted for slower interruption rates (e.g., 10 interruptions per second); the masking effects were minimal. Recent studies of interrupted speech have avoided this issue by shaping the rise-fall times with a digital algorithm (e.g., Jin and Nelson, 2010; Wang and Humes, 2010). A second variable in the interrupted speech paradigm is the temporal location or placement of the interruptions (i.e., where in the waveform the interruptions occur). Here the issue is this: what parts of an utterance are necessary to enable intelligibility (e.g., Fogerty and Kewley-Port, 2009)? Interruptions may or may not disturb these necessary cues. Here is the prompting question: do shaped and unshaped rise-fall characteristics of the on-segments of interrupted speech produce the same or different recognition performances? A second question arises: are recognition performances on complementary halves of an interrupted signal the same or different? This study used a mixed-model design with two within-subject variables (unshaped and shaped rise-fall characteristic, complementary halves) and one between-subjects variable (listener group). A total of 12 young listeners (age range: 19-29 yr) with normal hearing and 12 older listeners (age range: 53-80 yr) with hearing loss for pure tones participated. A total of 95 consonant-vowel nucleus-consonant words were interrupted (10 interruptions per second; 50% duty cycle) by parsing alternate 50 msec segments to separate files, which provided complementary temporal halves of the target word referenced to word onset; the first on-segment of the 0 msec condition started at word onset, whereas the first on-segment of the 50 msec condition started 50 msec after word onset. The interruption routine either applied no shaping of the 4 msec rise-fall times or a cos² shape. Each listener received 25 practice words then a unique randomization of 280 interrupted words (70 words, 2 rise-fall shapes, and 2 interrupt onset conditions). The listeners with normal hearing performed 8-16% better on the various comparable conditions than did the older listeners with hearing loss. The mean performance differences between shaped and unshaped rise-fall characteristics ranged from <1-3% and were not significant. Performance was significantly 10-17% better on the 0 msec condition than on the 50 msec condition. There was no significant interaction between the two main variables, rise-fall shape, and onset time of the interruptions. The rise-fall shape of the onset and offset of the on-segment of the interruption cycle does not affect recognition performance of words. The location of the interruptions in a word can have a significant effect on recognition performance.

Effects of self-generated noise on estimates of detection threshold in quiet in school-age children and adults

Detection in quiet develops earlier in childhood for high than low frequencies. The present study tested the hypothesis that self-generated noise could play a role in this finding. When adults listen for sounds near threshold, they tend to engage in behaviors that reduce physiologic noise (e.g., quiet breathing), which is predominantly low frequency. Children may not suppress self-generated noise to the same extent as adults. This possibility was evaluated by measuring sound levels in the ear canal simultaneous with adaptive threshold estimation for 250-, 1000-, and 4000-Hz pure tones. Stimuli were delivered and recordings were made using a single foam insert. Listeners were children (4.3–16.0 yr) or adults. Consistent with previous data, the effect of child age was robust at 250 Hz, whereas thresholds of even the youngest listeners were nearly adult-like at 4000 Hz. The spectral shape of self-generated noise was generally similar across listener age groups, although the magnitude was higher in younger listeners. Trial-by-trial data were evaluated to assess the relationship between noise and the accuracy of listener responses: there was an association for younger listeners. These results provide preliminary evidence that self-generated noise may play a role in the prolonged development of low-frequency detection in quiet.

Effects of Speaker Emotional Facial Expression and Listener Age on Incremental Sentence Processing

We report two visual-world eye-tracking experiments that investigated how and with which time course emotional information from a speaker's face affects younger (N = 32, Mean age = 23) and older (N = 32, Mean age = 64) listeners’ visual attention and language comprehension as they processed emotional sentences in a visual context. The age manipulation tested predictions by socio-emotional selectivity theory of a positivity effect in older adults. After viewing the emotional face of a speaker (happy or sad) on a computer display, participants were presented simultaneously with two pictures depicting opposite-valence events (positive and negative; IAPS database) while they listened to a sentence referring to one of the events. Participants' eye fixations on the pictures while processing the sentence were increased when the speaker's face was (vs. wasn't) emotionally congruent with the sentence. The enhancement occurred from the early stages of referential disambiguation and was modulated by age. For the older adults it was more pronounced with positive faces, and for the younger ones with negative faces. These findings demonstrate for the first time that emotional facial expressions, similarly to previously-studied speaker cues such as eye gaze and gestures, are rapidly integrated into sentence processing. They also provide new evidence for positivity effects in older adults during situated sentence processing.