Monthly Archives: December 2007

Happy Holidays

The University of Texas at Dallas will be closed December 22-January 1.  New posts will start appearing on January 2.  Have a safe and happy holiday season.

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Functional analysis of swallowing outcomes after supracricoid partial laryngectomy

from Head and Neck

Abstract

Background.
In this study, we analyzed swallowing recovery after supracricoid partial laryngectomy (SCPL).

Methods.
We retrospectively reviewed 27 patients treated with SCPL (September 1997 to March 2005). We evaluated recovery course, nutritional outcomes, and swallowing using objective analysis. Modified barium swallow (MBS) study results identified swallowing physiology and therapeutic effectiveness.

Results.
Average length of hospitalization was 7.7 ± 9.2 days; time to decannulation was 5.3 ± 8.2 weeks. The most common complications included pneumonia and subcutaneous emphysema (26%). Twenty-two patients had MBS studies, in which initially, all patients aspirated due to neoglottic incompetency, and impaired base of tongue and laryngeal movements. Although aspiration rates did not change significantly over time, use of appropriately selected swallowing strategies effectively protected the airway (p = .0365). Ultimately, 81% of patients returned to complete oral intake with median tube removal at 9.4 weeks.

Conclusion.
SCPL produces severe dysphagia initially. Our findings suggest that objective swallowing assessment is important for return to oral nutrition after SCPL. © 2007 Wiley Periodicals, Inc. Head Neck, 2008

Auditory steady-state responses to multiple simultaneous stimuli in children with functional or sensorineural hearing loss

from the European Archives of Oto-Rhino-Laryngology

Abstract The goal of our study was to identify the role of auditory steady-state responses for hearing assessment in patients with functional hearing loss. The study design was to compare auditory steady-state response thresholds and standard pure-tone audiometry thresholds between patients with functional or sensorineural hearing loss. Subjects comprised 16 patients (24 ears) with functional hearing loss and 17 patients (24 ears) with sensorineural hearing loss. Differences and correlations between auditory steady-state response thresholds and standard pure-tone audiometry thresholds at 500, 1,000, 2,000 and 4,000 Hz were evaluated. In children with functional hearing loss, pure-tone audiometry thresholds and auditory steady-state response thresholds were significantly different at all frequencies and were not significantly correlated. In patients with sensorineural hearing loss, pure-tone audiometry thresholds and auditory steady-state response thresholds did not differ significantly at any frequencies and were significantly correlated. Auditory steady-state responses may have principal role in the assessment of auditory brainstem acuity, particularly at low frequencies in patients with functional hearing loss.

Intact inner speech use in autism spectrum disorder: evidence from a short-term memory task

from Journal of Child Psychology and Psychiatry

Background: Inner speech has been linked to higher-order cognitive processes including ‘theory of mind’, self-awareness and executive functioning, all of which are impaired in autism spectrum disorder (ASD). Individuals with ASD, themselves, report a propensity for visual rather than verbal modes of thinking. This study explored the extent to which children with ASD used inner speech or visual imagery to support recall from short-term memory.

Method: Twenty-five children with ASD and 20 comparison children with moderate learning disabilities completed an immediate serial recall task, in which stimuli consisted of items with either phonologically similar features, visuo-spatially similar features or control items which were neither visuo-spatially nor phonologically similar.

Results: ASD and comparison participants, with verbal mental ages above 7 years, recalled phonologically similar stimuli less well than control stimuli, indicating that both groups were using inner speech to recode visually presented information into a phonological code. In contrast, those participants with verbal mental ages below 7 years, whether with ASD or not, recalled visuo-spatially similar stimuli less well than control stimuli, indicating visual rather than phonological coding. This developmental pattern mirrors that found in typically developing children.

Conclusions: Under experimental conditions, individuals with ASD use inner speech to the same extent as individuals without ASD of a comparable mental age.

Voice outcomes after radiotherapy treatment for early glottic cancer: Assessment using multidimensional tools

from Head and Neck

Background.
This is the first prospective study to use instrumental and both clinician- and client-rated auditory-perceptual measures to examine voice and voice-related quality of life changes in patients after curative radiotherapy for early glottic cancer.

Method.
Thirty patients undergoing curative radiotherapy treatment for early glottic cancer completed the following: 3 voice tasks for acoustic, aerodynamic, and auditory-perceptual voice measures (therapist-rated); a patient self-report rating of voice quality; and a voice-related quality of life assessment before and 12 months after radiotherapy.

Results.
Patients’ perceptions of their voice quality and their voice-related quality of life significantly improved posttreatment, as did acoustic, aerodynamic, and auditory-perceptual voice measures. Mean speaking fundamental frequency did not change significantly, although breathiness and strain in the voice recordings were demonstrably reduced.

Conclusion.
In describing postradiotherapy voices in this study, pertinent measures of voice outcomes have been established, setting the benchmark for comparison in future cohort studies. © 2007 Wiley Periodicals, Inc. Head Neck, 2008

Durable effects of concentrated disadvantage on verbal ability among African-American children

from Docuticker

Disparities in verbal ability, a major predictor of later life outcomes, have generated widespread debate, but few studies have been able to isolate neighborhood-level causes in a developmentally and ecologically appropriate way. This study presents longitudinal evidence from a large-scale study of >2,000 children ages 6–12 living in Chicago, along with their caretakers, who were followed wherever they moved in the U.S. for up to 7 years. African-American children are exposed in such disproportionate numbers to concentrated disadvantage that white and Latino children cannot be reliably compared, calling into question traditional research strategies assuming common points of overlap in ecological risk. We therefore focus on trajectories of verbal ability among African-American children, extending recently developed counterfactual methods for time-varying causes and outcomes to adjust for a wide range of predictors of selection into and out of neighborhoods. The results indicate that living in a severely disadvantaged neighborhood reduces the later verbal ability of black children on average by {approx} 4 points, a magnitude that rivals missing a year or more of schooling.

GenVec Announces NIH Funding For Balance And Hearing Loss Program

from Medical News Today.com

GenVec, Inc. (Nasdaq:GNVC) announced that it has received a sub-award under a grant from the National Institute on Deafness and Other Communication Disorders (NIDCD), of the National Institutes of Health (NIH), to develop a gene-based drug therapy to treat severe balance disorders. GenVec will receive up to $1,125,000 over five years to support pre-clinical research in collaboration with Dr. Hinrich Staecker, University of Kansas Medical Center, leading to the development of a drug candidate for clinical testing.

Tone-deafness linked to size of grey matter

from CTV.ca

Daring to dislike Christmas carols is often enough to be branded a hard-headed humbug, but a new study shows the size of a person’s grey matter can actually have an impact on one’s appreciation of music.
In a study published recently in the Journal of Neuroscience, researchers at McGill University and the Universite de Montreal claim the tone-deaf have a thicker cortex in certain parts of their brain.

Endogenous Cortical Rhythms Determine Cerebral Specialization for Speech Perception and Production

from Neuron

Across multiple timescales, acoustic regularities of speech match rhythmic properties of both the auditory and motor systems. Syllabic rate corresponds to natural jaw-associated oscillatory rhythms, and phonemic length could reflect endogenous oscillatory auditory cortical properties. Hemispheric lateralization for speech could result from an asymmetry of cortical tuning, with left and right auditory areas differentially sensitive to spectro-temporal features of speech. Using simultaneous electroencephalographic (EEG) and functional magnetic resonance imaging (fMRI) recordings from humans, we show that spontaneous EEG power variations within the gamma range (phonemic rate) correlate best with left auditory cortical synaptic activity, while fluctuations within the theta range correlate best with that in the right. Power fluctuations in both ranges correlate with activity in the mouth premotor region, indicating coupling between temporal properties of speech perception and production. These data show that endogenous cortical rhythms provide temporal and spatial constraints on the neuronal mechanisms underlying speech perception and production.

Abstract Coding of Audiovisual Speech: Beyond Sensory Representation

from Neuron

Is there a neural representation of speech that transcends its sensory properties? Using fMRI, we investigated whether there are brain areas where neural activity during observation of sublexical audiovisual input corresponds to a listener’s speech percept (what is “heard”) independent of the sensory properties of the input. A target audiovisual stimulus was preceded by stimuli that (1) shared the target’s auditory features (auditory overlap), (2) shared the target’s visual features (visual overlap), or (3) shared neither the target’s auditory or visual features but were perceived as the target (perceptual overlap). In two left-hemisphere regions (pars opercularis, planum polare), the target invoked less activity when it was preceded by the perceptually overlapping stimulus than when preceded by stimuli that shared one of its sensory components. This pattern of neural facilitation indicates that these regions code sublexical speech at an abstract level corresponding to that of the speech percept.

Sound localization with communications headsets: Comparison of passive and active systems

from Noise & Health

Studies have demonstrated that conventional hearing protectors interfere with sound localization. This research examines possible benefits from advanced communications devices. Horizontal plane sound localization was compared in normal-hearing males with the ears unoccluded and fitted with Peltor H10A passive attenuation earmuffs, Racal Slimgard II communications muffs in active noise reduction (ANR) and talk-through-circuitry (TTC) modes and Nacre QUIETPRO TM communications earplugs in off (passive attenuation) and push-to-talk (PTT) modes. Localization was assessed using an array of eight loudspeakers, two in each spatial quadrant. The stimulus was 75 dB SPL, 300-ms broadband noise. One block of 120 forced-choice loudspeaker identification trials was presented in each condition. Subjects responded using a laptop response box with a set of eight microswitches in the same configuration as the speaker array. A repeated measures ANOVA was applied to the dataset. The results reveal that the overall percent correct response was highest in the unoccluded condition (94%). A significant reduction of 24% was observed for the communications devices in TTC and PTT modes and a reduction of 49% for the passive muff and plug and muff with ANR. Disruption in performance was due to an increase in front-back reversal errors for mirror image spatial positions. The results support the conclusion that communications devices with advanced technologies are less detrimental to directional hearing than conventional, passive, limited amplification and ANR devices.

Factorial validity of the noise sensitivity questionnaire

from Noise & Health

The Noise Sensitivity Questionnaire (NoiSeQ) aims at the measurement of global noise sensitivity as well as the sensitivity for five domains of everyday life namely ‘Leisure’, ‘Work’, ‘Habitation’, ‘Communication’ and ‘Sleep’. The present investigation examined the factorial validity of the NoiSeQ to determine whether the items of the NoiSeQ cover the different factors as assumed. The analysis was done using the method of Confirmatory Factor Analysis (CFA). The linear structural model took into consideration only the scales of the NoiSeQ for which reliability could be demonstrated, namely, ‘Sleep’, ‘Communication’, ‘Habitation’ and ‘Work’. The linear structural model presumed that each of the 28 items has a relation only to one corresponding factor. Furthermore, the model allowed for correlations between the four factors. The data base encompassed 293 persons. Parameter estimation was based on the General Least Square method. The data was checked with respect to the occurrence of multivariate outliers, deviation from multivariate normality and existing collinearities. The data met the overall requirements of a CFA. The evaluation of model fit was based on the relative chi2 -value, the Root Mean Square Error of Approximation, the Goodness of Fit Index, the Adjusted Goodness of Fit Index and the Root Mean Square Residual. All fit indices indicated an acceptable match of the model. As the postulated structure of the NoiSeQ was consistent with the empirical data, the classification of the items as well as the claimed interdependencies between the scales can be maintained. The regression weights of all items as well as the correlations between the latent variables were statistically significant. The estimated reliability of the latent variables took values of >/=0.84. The findings generally justified the conclusion that there is no urgent need to modify the four scales of the NoiSeQ thus, indicating the factorial validity of the NoiSeQ.

Effects of binaural electronic hearing protectors on localization and response time to sounds in tEffects of binaural electronic hearing protectors on localization and response time to sounds in the horizontal planehe horizontal plane

from Noise & Health

The effects of electronic hearing protector devices (HPDs) on localization and response time (RT) to stimuli were assessed at six locations in the horizontal plane. The stimuli included a firearm loading, telephone ringing and .5-kHz and 4-kHz tonebursts presented during continuous traffic noise. Eight normally hearing adult listeners were evaluated under two conditions: (a) ears unoccluded; (b) ears occluded with one of three amplitude-sensitive sound transmission HPDs. All HPDs were found to affect localization, and performance was dependent on stimuli and location. Response time (RT) was less in the unoccluded condition than for any of the HPD conditions for the broadband stimuli. In the HPD conditions, RT to incorrect responses was significantly less than RT to correct responses for 120 degrees and 240 degrees , the two locations with the greatest number of errors. The RTs to incorrect responses were significantly greater than to correct responses for 60 degrees and 300 degrees , the two locations with the least number of errors. The HPDs assessed in this study did not preserve localization ability under most stimulus conditions.

New Brain Mechanism Identified For Interpreting Speech

from Medical News Today.com

In conversation, humans recognize words primarily from the sounds they hear. However, scientists have long known that what humans perceive goes beyond the sounds and even the sights of speech. The brain actually constructs its own unique interpretation, factoring in both the sights and sounds of speech.

How do I sound to me? Perceived changes in communication in Parkinson’s disease

from Clinical Rehabilitation

Objective: To examine self and carer perceived changes in communication associated with Parkinson’s disease and relate these to speech intelligibility, gender, age and other disease measures.

Design: Cross-sectional survey of a hospital- and community-based sample of 176 people with Parkinson’s disease and their carers using a questionnaire based on semantic differential techniques.

Participants: One hundred and four people with Parkinson’s disease with no history of communication difficulties prior to onset of their Parkinson’s disease and 45 primary carers who returned completed questionnaires.

Main outcome measures: Differences in ratings for `before’ the onset of Parkinson’s disease versus present status.

Results: There was a strong perception of negative impact on communication between `before’ and `now’, irrespective of age and gender and largely independent of disease severity and duration, intelligibility and cognitive status. Activities of daily living (assessed by Unified Parkinson’s Disease Rating Scale (UPDRS) II) and depression rating scale scores had the strongest association with change (adjusted R 2 0.27). There was a significant correlation between the rank order of perceived change in features examined in people with Parkinson’s disease versus their carers, though in general carers rated change as having less impact.

Conclusions: Parkinson’s disease exercises a strong influence on communication even before apparent alterations to intelligibility or motor status (UPDRS).