CUNY Sentences Research Articles

Recognition of vocoded speech in English by Mandarin-speaking English-learners

The purpose of this study was to examine the impact of spectral degradation on speech processing in non-native listeners. The participants included 27 native English (L1) listeners and 43 native Mandarin listeners who learned English as a second language (L2). The speech stimuli included 12 English vowels embedded in a /hVd/ context, 20 English consonants embedded in a /Ca/ context, and HINT, CUNY, and R-SPIN sentences. All stimuli were processed using 2-, 4-, 6-, 8-, and 12-channel noise vocoders. The results showed that compared to the L1 listeners, the L2 listeners demonstrated less improvement in phoneme recognition with increasing number of channels, which was associated with the phoneme confusions due to the impact of their native language. Both consonant and vowel recognition made significant contributions to sentence recognition in the L2 listeners. In addition, the L2 listeners were less effective than the L1 listeners in applying contextual information and linguistic knowledge to sentence recognition. However, the facilitating role of contextual cues in sentence recognition was consistently present in the L2 listeners but they required more spectral information to maximize the contextual benefit in comparison to the L1 listeners. The overall perceptual performance of the L2 listeners was positively correlated with and predicted by the length of residence in the U.S.

Audio‐visual speech perception is associated with cerebral tau deposition on [18F]flortaucipir PET

AbstractBackgroundSensory impairments are associated with dementia and biomarkers of pathology. In a preliminary study, we evaluated whether audio‐visual speech perception, which involves integration of complementary phonetic information from two sensory modalities (vision and hearing), is associated with AD neuropathology on imaging.Method14 individuals (2 cognitive normal (CN), 7 subjective cognitive decline (SCD), 4 MCI, and 1 AD) from the Indiana Alzheimer Disease Center and Indiana Memory and Aging Study underwent auditory testing, MRI, amyloid PET with [18F]florbetaben, and tau PET with [18F]flortaucipir. The audiologic testing included a brief pure‐tone hearing screen, followed by CUNY Sentences [1], among other tests. CUNY Sentences are presented using auditory input only (Auditory condition (A)) or using both auditory and visual input (AV using video with sound of an individual saying sentences). Words and sentences correct are scored, as is the difference between word and sentence scores (ΔWdtoSent). Amyloid and tau PET were processed using standard techniques. Mean SUVR from the cortex (amyloid and tau) and lateral temporal lobe (LTL; tau) were extracted. MRI was processed with Freesurfer v6 to extract LTL thickness. Because the CUNY scores were skewed, Spearman correlations were used to assess relations of sentence scores and ΔWdtoSent for both the A and AV conditions with neuroimaging measures of AD pathology (cortical amyloid, LTL and cortical tau, and LTL thickness). Inclusion of age, sex, and ICV where appropriate did not alter the observed results.ResultsSignificant associations between AV speech perception for sentences and AV ΔWdtoSent and tau deposition in the LTL and cortex were observed (Figure 1). These results remained significant after the AD participant was removed. Only trend associations were observed for the A condition, which were less robust than in the AV condition. Finally, a trend for a significant association with LTL thickness was observed. No association with amyloid was observed.ConclusionIntegration of phonetic information from two sensory modalities (vision and hearing) may be a potential a biomarker for tau pathology in patients at risk for AD. Future studies with larger samples and longitudinal follow‐up are needed. Reference: [1] Boothroyd et al. (1988) Ear and Hearing.

Cochlear Implant Outcomes in Patients With Severe Compared With Profound Hearing Loss

To compare the speech perception outcomes for patients with preoperative severe versus profound hearing loss with a cochlear implant (CI). Retrospective patient review. Cochlear implant program. Cochlear implant adult recipients (16 yr and above) having surgery between 2008 and 2015 with speech perception results and four frequency averaged severe (70-89 dBHL) or profound (90 dBHL and above) hearing loss. Prelingual deaf adults were included in the data. Cochlear implant. Speech perception scores with CUNY sentences and monosyllabic (CNC/CVC) word scores at preoperative and 3, 6, and 12 months postoperatively testing. Mann-Whitney U test was performed to compare outcomes of the two groups. Interquartile comparisons were also made. The severe group had significantly better speech perception than the profound hearing loss group for CUNY sentences and CNC/CVC word scores preoperatively (p < 0.001) (p < 0.001), at 6 months (p < 0.001) (p < 0.001), and at 12 months (p < 0.01) (p < 0.001), respectively. At 3 months there was no significant difference. The number of patients in each severe or profound group at the different time points ranged from 92 to 367 patients for CUNY sentences and from 52 to 216 patients for the word scores. The 12 months' lower quartile score for CUNY sentences for severe and profound groups was 83% and 75% respectively. The lower quartile score for words was 32% and 26% respectively. Adult CI recipients showed marked improvements in speech perception with a CI. Those with severe hearing loss have significantly better outcomes compared with profound hearing loss patients. These outcomes can inform CI candidacy evaluation criteria.

Effects of electrode deactivation on speech recognition in multichannel cochlear implant recipients

Objectives: The objective of the current study is to evaluate how speech recognition performance is affected by the number of active electrodes that are turned off in multichannel cochlear implants. Several recent studies have demonstrated positive effects of deactivating stimulation sites based on an objective measure in cochlear implant processing strategies. Previous studies using an analysis of variance have shown that, on average, cochlear implant listeners’ performance does not improve beyond eight active electrodes. We hypothesized that using a generalized linear mixed model would allow for better examination of this question.Methods: Seven peri- and post-lingual adult cochlear implant users (eight ears) were tested on speech recognition tasks using experimental MAPs which contained either 8, 12, 16 or 20 active electrodes. Speech recognition tests included CUNY sentences in speech-shaped noise, TIMIT sentences in quiet as well as vowel (CVC) and consonant (CV) stimuli presented in quiet and in signal-to-noise ratios of 0 and +10 dB.Results: The speech recognition threshold in noise (dB SNR) significantly worsened by approximately 2 dB on average as the number of active electrodes was decreased from 20 to 8. Likewise, sentence recognition scores in quiet significantly decreased by an average of approximately 12%.Discussion/conclusion: Cochlear implant recipients can utilize and benefit from using more than eight spectral channels when listening to complex sentences or sentences in background noise. The results of the current study suggest a conservative approach for turning off stimulation sites is best when using site-selection procedures.

Factors Affecting Speech Perception Improvement Post Implantation in Congenitally Deaf Adults.

To identify factors preimplantation associated with postimplantation speech perception improvement in the adult congenitally deaf population. Forty-four adult cochlear implant (CI) patients who had a severe to profound hearing loss from birth were identified from this centre's database. Eight preimplantation factors, speech intelligibility, preimplantation hearing levels, communication mode, preimplantation speech perception scores, progression of hearing loss, age at implantation, hearing aid use preimplantation, and gender, were recorded during the CI assessment process. These factors were investigated to determine their effect on speech perception improvement postimplantation. The outcome measures were the improvement in scores for the BKB Sentence test and CUNY Sentence test with lipreading after implantation. In the final analysis, 26 patients were included in the CUNY analysis, and 30 patients were included in the BKB analysis. Speech intelligibility rating, preimplantation hearing levels, and communication mode were shown to be significantly associated with improvements in speech perception postimplantation. Three factors were identified that affected speech perception improvement postimplantation: speech intelligibility, preimplantation hearing levels, and communication mode. These factors can be used to counsel CI patients regarding potential speech perception improvements from cochlear implantation, although these are based on average data and may not reflect individual performance.

Top-Down Processes in Simulated Electric-Acoustic Hearing: The Effect of Linguistic Context on Bimodal Benefit for Temporally Interrupted Speech.

Previous studies have documented the benefits of bimodal hearing as compared with a cochlear implant alone, but most have focused on the importance of bottom-up, low-frequency cues. The purpose of the present study was to evaluate the role of top-down processing in bimodal hearing by measuring the effect of sentence context on bimodal benefit for temporally interrupted sentences. It was hypothesized that low-frequency acoustic cues would facilitate the use of contextual information in the interrupted sentences, resulting in greater bimodal benefit for the higher context (CUNY) sentences than for the lower context (IEEE) sentences. Young normal-hearing listeners were tested in simulated bimodal listening conditions in which noise band vocoded sentences were presented to one ear with or without low-pass (LP) filtered speech or LP harmonic complexes (LPHCs) presented to the contralateral ear. Speech recognition scores were measured in three listening conditions: vocoder-alone, vocoder combined with LP speech, and vocoder combined with LPHCs. Temporally interrupted versions of the CUNY and IEEE sentences were used to assess listeners' ability to fill in missing segments of speech by using top-down linguistic processing. Sentences were square-wave gated at a rate of 5 Hz with a 50% duty cycle. Three vocoder channel conditions were tested for each type of sentence (8, 12, and 16 channels for CUNY; 12, 16, and 32 channels for IEEE) and bimodal benefit was compared for similar amounts of spectral degradation (matched-channel comparisons) and similar ranges of baseline performance. Two gain measures, percentage-point gain and normalized gain, were examined. Significant effects of context on bimodal benefit were observed when LP speech was presented to the residual-hearing ear. For the matched-channel comparisons, CUNY sentences showed significantly higher normalized gains than IEEE sentences for both the 12-channel (20 points higher) and 16-channel (18 points higher) conditions. For the individual gain comparisons that used a similar range of baseline performance, CUNY sentences showed bimodal benefits that were significantly higher (7% points, or 15 points normalized gain) than those for IEEE sentences. The bimodal benefits observed here for temporally interrupted speech were considerably smaller than those observed in an earlier study that used continuous speech. Furthermore, unlike previous findings for continuous speech, no bimodal benefit was observed when LPHCs were presented to the LP ear. Findings indicate that linguistic context has a significant influence on bimodal benefit for temporally interrupted speech and support the hypothesis that low-frequency acoustic information presented to the residual-hearing ear facilitates the use of top-down linguistic processing in bimodal hearing. However, bimodal benefit is reduced for temporally interrupted speech as compared with continuous speech, suggesting that listeners' ability to restore missing speech information depends not only on top-down linguistic knowledge but also on the quality of the bottom-up sensory input.

Cochlear implants for pre-lingually profoundly deaf adults

Introduction: Increasing numbers of pre-lingually profoundly deaf adults are seeking a cochlear implant (CI). Pre- and post-operative outcomes are presented on 20 of these patients.Results: An Adult Pre-Lingually Profoundly Deaf Implant Profile (APDIP) weighted the pre-operative level of concern about potential CI benefit. Results indicated no group mean post-operative open-set improvement. However CUNY sentence testing (auditory plus lip-reading cues) revealed improved performance with a CI. Twelve out of 20 patients used their CIs for more than 10 hours per day, suggesting good usage. Moreover, hours of usage were positively associated with measured benefit on CUNY sentences in the lip-reading plus sound via CI condition. There was no apparent relationship between pre-operative level of concern and post-operative CI performance or hours of processor use.Conclusion: Results suggest implantation is beneficial and effective in this group.

Speech perception scores in cochlear implant recipients: An analysis of ceiling effects in the CUNY sentence test (Quiet) in post-lingually deafened cochlear implant recipients

Objectives: To evaluate the clinical utility of the City University of New York sentence test in a cohort of post-lingually deafened cochlear implants recipients over time.Methods: 117 post-lingually deafened, Australian English-speaking CI recipients aged between 23 and 98 years (M = 66 years; SD = 15.09) were recruited. CUNY sentence test scores in quiet were collated and analysed at two cut-offs, 95% and 100%, as ceiling scores.Results: CUNY sentence scores ranged from 4% to 100% (M = 86.75; SD = 20.65), with 38.8% of participants scoring 95% and 16.5% of participants reaching the 100% scores. The percentage of participants reaching the 95% and 100% ceiling scores increased over time (6 and 12 months post-implantation).The distribution of all post-operative CUNY test scores skewed to the right with 82% of test scores reaching above 90%.Discussion: This study demonstrates that the CUNY test cannot be used as a valid tool to measure the speech perception skills of post-lingually deafened CI recipients over time. This may be overcome by using adaptive test protocols or linguistically, cognitively or contextually demanding test materials.Conclusion: The high percentage of CI recipients achieving ceiling scores for the CUNY sentence test in quiet at 3 months post-implantation, questions the validity of using CUNY in CI assessment test battery and limits its application for use in longitudinal studies evaluating CI outcomes. Further studies are required to examine different methods to overcome this problem.

Influence of Test Condition on Speech Perception With Electric-Acoustic Stimulation.

The goal of this work was to better understand speech perception for cochlear implant (CI) users with bilateral residual hearing, including consideration of effects related to listening conditions and test measures. Of interest was the role of acoustic hearing for speech perception in a complex background, the role of listening experience for CI-alone conditions, and whether performance with electric-acoustic stimulation (EAS) was improved by a contralateral hearing aid (HA). Eleven subjects provided data on Consonant-Nucleus-Consonant (CNC; Peterson & Lehiste, 1962) words in quiet, City University of New York (CUNY; Boothroyd, Hanin, & Hnath, 1985) sentences in steady noise, and Bamford-Kowal-Bench (Bench, Kowal, & Bamford, 1979) sentences in multitalker babble. Listening conditions included: CI with a full-frequency map, CI with a truncated-frequency map, EAS, and EAS+HA (EAS plus contralateral HA). Sounds were presented at 0° azimuth. For CNC words and CUNY sentences, performance was better with the truncated-frequency than the full-frequency map, and performance with EAS was better than for either CI-alone condition. For Bench-Kowal-Bamford sentences, EAS+HA was better than EAS. As demonstrated previously, performance was better in the EAS condition than either CI-alone condition. Better performance in the truncated-frequency than full-frequency CI-alone condition suggests that listening experience may be important. A contralateral HA improved performance over unilateral EAS under some conditions.

Effects of Site-Specific Level Adjustments on Speech Recognition With Cochlear Implants

Modulation detection thresholds (MDTs) vary across stimulation sites in a cochlear implant (CI) electrode array in a manner that is subject and ear specific. Previous studies have demonstrated that speech recognition with a CI can be improved by site-selection strategies, where selected stimulation sites with poor modulation sensitivity are removed from a subject's processor MAP. Limitations of site-selection strategies are that they can compromise spectral resolution and distort frequency-place mapping because the frequencies assigned to the removed sites are usually reallocated to other sites, and site bandwidths are broadened. The objective of the present study was to test an alternative approach for rehabilitation that aimed at improving the across-site mean MDTs by adjusting stimulation parameters at the poorly performing sites. On the basis of previous findings that modulation detection contributes to speech recognition and improves significantly with stimulus level, the authors hypothesized that modulation sensitivity at the poor sites could be improved by artificially increasing stimulation levels at those sites in the speech processor, which then would lead to improved speech recognition. Nine postlingually deafened ears implanted with Nucleus CIs were evaluated for MDTs, absolute-detection threshold levels (T levels), and the maximum loudness levels (C levels) on each of the available stimulation sites. For each ear, the minimum stimulation level settings in the speech-processor MAP were raised by 5%, and alternatively by 10%, of the dynamic range (DR) from true thresholds on five stimulation sites with the poorest MDTs. For comparison, a 5% level raise was applied globally to all stimulation sites. The C levels were fixed during these level manipulations. MDTs at the five poorest stimulation sites were compared at 20% DR before and after the level adjustments. Speech-reception thresholds (SRTs), that is, signal to noise ratios required for 50% correct speech recognition, were evaluated for these MAPs using CUNY sentences. The site-specific level-adjusted MAPs were compared with the global-level-adjusted MAP and the MAP without level adjustment. The effects on speech recognition of adjusting the minimal stimulation level settings on the five poorest stimulation sites were also compared with effects of removing these sites from the speech-processor MAP. The 5% level increase on the five electrodes with the worst MDTs resulted in an improvement in the group mean SRT of 2.36 dB SNR relative to the MAP without level adjustment. The magnitude of level increase that resulted in the greatest SRT improvement for individuals varied across ears. MDTs measured at 20% DR significantly improved on the poor sites after the level adjustment that resulted in the best SRT for that ear was applied. Increasing the minimal stimulation levels on all stimulation sites or removing sites selected for rehabilitation, the parsimonious approaches, did not improve SRTs. The site-specific adjustments of the T level settings improved modulation sensitivity at low levels and significantly improved subjects' SRTs. Thus, this site-rehabilitation strategy was an effective alternative to site-selection strategies for improving speech recognition in CI users.

Sentence comprehension in aphasia: A noisy channel approach

Sentence comprehension in aphasia: A noisy channel approach

Some normative data on lip-reading skills (L)

The ability to obtain reliable phonetic information from a talker's face during speech perception is an important skill. However, lip-reading abilities vary considerably across individuals. There is currently a lack of normative data on lip-reading abilities in young normal-hearing listeners. This letter describes results obtained from a visual-only sentence recognition experiment using CUNY sentences and provides the mean number of words correct and the standard deviation for different sentence lengths. Additionally, the method for calculating T-scores is provided to facilitate the conversion between raw and standardized scores. This metric can be utilized by clinicians and researchers in lip-reading studies. This statistic provides a useful benchmark for determining whether an individual's lip-reading score falls within the normal range, or whether it is above or below this range.

Reproducibility of fMRI activations associated with auditory sentence comprehension

The reproducibility of three different aspects of fMRI activations—namely binary activation maps, effect size and spatial distribution of local maxima—was evaluated for an auditory sentence comprehension task with high attention demand on a group of 17 subjects that were scanned on five different occasions. While in the scanner subjects were asked to listen to a series of six short everyday sentences from the CUNY sentence test. Comprehension and attention to the stimuli were monitored after each listen condition epoch by having subjects answer a series of multiple-choice questions. Statistical maps of activation for the listen condition were computed at three different levels: overall results for all imaging sessions, group-level/single-session results for each of the five imaging occasions, and single-subject/single-session results computed for each subject and each scanning occasion independently. The experimental task recruited a distributed bilateral network with processing nodes located in the lateral temporal cortex, inferior frontal cortex, medial BA6, medial occipital cortex and subcortical structures such as the putamen and the thalamus. Reproducibility of these activations at the group level was high (83.95% of the imaged volume was consistently classified as active/inactive across all five imaging sessions), indicating that sites of neuronal activity associated with auditory comprehension can reliably be detected with fMRI in healthy subjects, across repeated measures after group averaging. At the single-subject level reproducibility ranged from moderate to high, although no significant differences were found on behavioral measures across subjects or sessions. This result suggests that contextual differences—i.e., those specific to each imaging session, can modulate our ability to detect fMRI activations associated with speech comprehension in individual subjects.

Aging, Audiovisual Integration, and the Principle of Inverse Effectiveness

The purpose of this investigation was to compare the ability of young and older adults to integrate auditory and visual sentence materials under conditions of good and poor signal clarity. The principle of inverse effectiveness (PoIE), which characterizes many neuronal and behavioral phenomena related to multisensory integration, asserts that as unimodal performance declines, integration is enhanced. Thus, the PoIE predicts that both young and older adults will show enhanced integration of auditory and visual speech stimuli when these stimuli are degraded. More importantly, because older adults' unimodal speech recognition skills decline in both the auditory and visual domains, the PoIE predicts that older adults will show enhanced integration during audiovisual speech recognition relative to younger adults. This study provides a test of these predictions. Fifty-three young and 53 older adults with normal hearing completed the closed-set Build-A-Sentence test and the CUNY Sentence test in a total of eight conditions; four unimodal and four audiovisual. In the unimodal conditions, stimuli were either auditory or visual and either easier or harder to perceive; the audiovisual conditions were formed from all the combinations of the unimodal signals. The hard visual signals were created by degrading video contrast, and the hard auditory signals were created by decreasing the signal to noise ratio. Scores from the unimodal and bimodal conditions were used to compute auditory enhancement and integration enhancement measures. Contrary to the PoIE, neither the auditory enhancement nor integration enhancement measures increased when signal clarity in the auditory or visual channel of audiovisual speech stimuli was decreased, nor was either measure higher for older adults than for young adults. In audiovisual conditions with easy visual stimuli, the integration enhancement measure for older adults was equivalent to that for young adults. However, in conditions with hard visual stimuli, integration enhancement for older adults was significantly lower than that for young adults. The present findings do not support extension of the PoIE to audiovisual speech recognition. Our results are not consistent with either the prediction that integration would be enhanced under conditions of poor signal clarity or the prediction that older adults would show enhanced integration, relative to young adults. Although there is a considerable controversy with regard to the best way to measure audiovisual integration, the fact that two of the most prominent measures, auditory enhancement and integration enhancement, both yielded results inconsistent with the PoIE, strongly suggests that the integration of audiovisual speech stimuli differs in some fundamental way from the integration of other bimodal stimuli. The results also suggest that aging does not impair integration enhancement when the visual speech signal has good clarity, but may affect it when the visual speech signal has poor clarity.

Speech Discrimination Scores Using the Latest Generation of Speech Processors

The Manchester Cochlear Implant Programme was established in 1988 and over 1000 patients have been implanted to date. Developments and improvements in cochlear implant technology over the past 21 years have resulted in new generations of implants and speech processors becoming available for use with patients. Since 2004, our patients have been asked to choose a device, based on their own preferences.This study looks at the speech discrimination scores of adults fitted with the latest generation of speech processors, including the Freedom (n = 40), the Harmony (n = 3) and the Opus 2 (n = 7). These scores are also compared to those of patients using earlier generations of speech processors, including the Esprit 3G (n = 89), the Auria (n = 9) and the Tempo+ (n = 38).Speech discrimination assessments (CUNY sentences, BKB sentences (in quiet and in noise) and AB words) were undertaken at the following intervals: 1 week, 3 months, 9 months and 21 months post switch-on. Patients were grouped according to their speech processor type and speech discrimination scores compared across the 6 groups.Our findings show that patients using the newer generation of speech processors tend to have higher speech discrimination scores than those using older generations of processor.

The association of codeine, macrocytosis and bilateral sudden or rapidly progressive profound sensorineural deafness

Conclusions. Codeine shows a similar association with profound deafness to other opiates. Good cochlear implant outcomes suggest a sensory disorder. Although macrocytosis could be due to confounding factors, the lack of other consistent findings may signify a vascular pathology. Objectives. To describe a series of patients identified as codeine users after referral for cochlear implantation. Patients and methods. This was a retrospective case series review. Patients were identified by the senior audiologist. Information regarding mode of onset of deafness, past medical history, drug and alcohol history, investigations and audiological outcomes following cochlear implantation was collected from hospital records and patient questionnaires. Results. Ten patients were included in the study. All patients had taken codeine phosphate and paracetamol in combination for several years, usually at greater than recommended daily dose. All patients presented with sudden or rapidly progressive bilateral deafness. All patients had a significant macrocytosis at the time of deafness (mean cell volume (MCV): mean 115 fL; range 105–132 fL). No other investigation was consistently abnormal. Four patients had a history of alcoholism. Seven patients had abnormal liver function tests. Patients usually performed well with cochlear implants (CUNY sentence scores without lip reading >90% in 9 of 10 patients).

Multicenter U.S. Bilateral MED-EL Cochlear Implantation Study: Speech Perception over the First Year of Use

Binaural hearing has been shown to support better speech perception in normal-hearing listeners than can be achieved with monaural stimulus presentation, particularly under noisy listening conditions. The purpose of this study was to evaluate whether bilateral electrical stimulation could confer similar benefits for cochlear implant listeners. A total of 26 postlingually deafened adult patients with short duration of deafness were implanted at five centers and followed up for 1 yr. Subjects received MED-EL COMBI 40+ devices bilaterally; in all but one case, implantation was performed in a single-stage surgery. Speech perception testing included CNC words in quiet and CUNY sentences in noise. Target speech was presented at the midline (0 degrees), and masking noise, when present, was presented at one of three simulated source locations along the azimuth (-90, 0, and +90 degrees). Benefits of bilateral electrical stimulation were observed under conditions in which the speech and masker were spatially coincident and conditions in which they were spatially separated. Both the "head shadow" and "summation" effects were evident from the outset. Benefits consistent with "binaural squelch" were not reliably observed until 1 yr after implantation. These results support a growing consensus that bilateral implantation provides functional benefits beyond those of unilateral implantation. Longitudinal data suggest that some aspects of binaural processing continue to develop up to 1 yr after implantation. The squelch effect, often reported as absent or rare in previous studies of bilateral cochlear implantation, was present for most subjects at the 1 yr measurement interval.

Clinical Evaluation of Expanded Input Dynamic Range in Nucleus Cochlear Implants

The aim of this study was to investigate whether expanded instantaneous input dynamic ranges (IIDRs) in the Nucleus cochlear implant system benefit speech perception in the laboratory and listening in the real world. Until recently, Nucleus cochlear implants have used an IIDR of approximately 30 dB. In this study, an IIDR of 31 dB was compared with 46 dB and 56 dB in the SPEAR3 research processor with nine adult implant recipients. Subjects were given two, 2-wk blocks of take-home experience with each of the three IIDRs. A single IIDR setting was used in each trial period. During the take-home experience with the expanded IIDRs, subjects used two programs: a standard program (with clinically measured electrode dynamic ranges) and a program with adjusted thresholds (decreased T levels). After each block of take-home experience, speech perception testing was conducted for CNC words in quiet (at 45 dB and 55 dB SPL) and for CUNY sentences in the presence of multi-taker babble. On average, CNC word recognition at low presentation levels was significantly better with the 46 dB and 56 dB IIDRs, compared with the 31 dB IIDR; however, there was no significant difference between the 46 dB and 56 dB IIDR conditions. These benefits were greater for standard programs than for reduced T level programs. For CUNY sentences in babble, group results indicated no significant difference in performance across IIDR. The three IIDRs were rated similarly in real-life listening situations, and two of the subjects expressed tolerance problems with the expanded standard IIDRs. IIDRs of 46 and 56 dB provided benefit in accessing low-level speech without a decrement in sentence perception in babble. Most subjects accepted the standard, wider IIDR programs in everyday life. No significant differences were found between the 46 dB and 56 dB IIDR programs.

Lexical mediation and context effects in sentence processing

Studies of syntactic ambiguity resolution have played a central role in resolving questions about when and how contextual information affects parsing processes. These investigations are often couched in terms of modularity versus interaction, with demonstrations of rapid contextual effects being taken as evidence that the mechanisms responsible for structuring sentences are permeable to referential or semantic context, and therefore non-modular. In this paper, we will propose that argument relations are constructed on the basis of lexically stored syntactic representations (as in MacDonald, M.C., Pearlmutter, N.J., and Seidenberg, M.S. (1994). Lexical nature of syntactic ambiguity resolution. Psychological Review, 101, 676–703. Pickering, M.J., and Traxler, M.J. (2004). Grammatical repetition and garden path effects. Paper presented to the CUNY Sentence Processing Conference. College Park, MD., Pickering, M.J., and Traxler, M.J. (2006). Syntactic Priming in Comprehension. Manuscript in preparation. Traxler, M.J., and Pickering, M.J. (2005, March). Syntactic priming in comprehension. Paper presented to the CUNY Sentence Processing Conference. Tucson, AZ), but that other types of structural decisions are made on the basis of general processing principles. This formulation can be tested by looking at how the parser reacts to immediate intra- and inter-sentential factors (short-term context) and how it reacts to patterns of input over longer time scales (long-term context). We begin with a brief review of work on context effects in syntactic disambiguation, sketch our account of parsing, and then provide evidence from two eye-tracking experiments that illustrate some of the processing principles that govern parsing of argument relations.

Effects of Insertion Depth of Cochlear Implant Electrodes upon Speech Perception

Objective: To investigate whether the insertion depth of a cochlear implant array affects postoperative speech perception. Design: The subjects were 48 postlingually deaf adults who received either the Nucleus 22 or the Nucleus 24 cochlear implant with a straight array. A postoperative radiograph of the cochlear electrode was used to estimate insertion depth, as either the angle of the electrode tip (angle) or the intracochlear length of the electrode (length). Other estimates of insertion depth included the numbers of active electrodes and channels used by the speech processor. Electrode depth, together with the duration of deafness, hearing aid usage, pre-operative speech perception score and pre-operative pure-tone averages were independent variables in a forward stepwise multiple regression analysis, where the dependent variables were postoperative CNC words and CNC phonemes. Results: Duration of deafness and insertion depth (angle, insertion length or active electrodes) were the predictive variables for CNC words or CNC phonemes. Angle was the best ‘depth-related’ predictor of postoperative speech perception. An even clearer relationship was found between CUNY sentences in noise and angle, in a subset of 26 patients. Conclusion: Depth of electrode insertion affects postoperative speech perception.