Consonant perception with linear and compression amplification

The consonant perception of 15 subjects with mild to moderate sensorineural hearing loss was evaluated using linear amplification and two different types of compression amplification. A specially modified hearing aid was used which allowed for variation of the amplifier input/output function in three steps, such that the compression ratio could be set to 1 (linear), 1.3 or 1.8. The Nonsense Syllable Test (NST) was recorded through the aid in quiet and in two different noise conditions (four-talker babble and a background noise with sharp intermittent sounds), and replayed to the listeners through headphones. No differences in consonant perception were found between the different types of amplification in the quiet condition. In the babble condition, consonant perception was significantly better with linear amplification than with either form of compression. In the sharp noise condition, there was no difference in performance between linear amplification and compression amplification with the ratio of 1.8. Consonant perception was adversely affected, however, by the compression and amplification with the ratio of 1.3 in this condition. Overall NST results and results for particular classes of consonants are discussed.     

Point-light facial displays enhance comprehension of speech in noise

Seeing a talker's face can improve the perception of speech in noise. There is little known about which characteristics of the face are useful for enhancing the degraded signal. In this study, a point-light technique was employed to help isolate the salient kinematic aspects of a visible articulating face. In this technique, fluorescent dots were arranged on the lips, teeth, tongue, cheeks, and jaw of an actor. The actor was videotaped speaking in the dark, so that when shown to observers, only the moving dots were seen. To test whether these reduced images could contribute to the perception of degraded speech, noise-embedded sentences were dubbed with the point-light images at various signal-to-noise ratios. It was found that these images could significantly improve comprehension for adults with normal hearing and that the images became more effective as participants gained experience with the stimuli. These results have implications for uncovering salient visual speech information as well as in the development of telecommunication systems for listeners who are hearing impaired.     

Syntactic and thematic processing in sentence comprehension: Evidence for a temporal dissociation.

The time courses for processing constituent structure relations, subcategorization restrictions, and thematic role relations during sentence comprehension were measured with reaction time and speed–accuracy trade-off variants of a grammaticality judgment task. Thematic role processing was found to be delayed by as much as 100 ms relative to the time when constituent structure and subcategorization information were processed. These data suggest a model of sentence comprehension in which the construction of a syntactic representation temporally leads the construction of a more embellished thematic representation. Serial and parallel variants of such a model are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Review of research on the intelligibility and comprehension of accelerated speech.

Time-compressed or accelerated speech is speech which has been reproduced in less than the original production time. Such speech may prove to be useful in a variety of situations in which people must rely upon listening to obtain the information specified by language. It may also prove to be a useful tool in studying the temporal requirements of the listener as he processes spoken language. Methods for the generation of time compressed speech are reviewed. Methods for the assessment of the effect of compression on word intelligibility and listening comprehension are discussed. Experiments dealing with the effect of time compression upon word intelligibility and upon the comprehensibility of connected discourse, and experiments concerned with the influence of stimulus variables, such as signal distortion, and organismic variables such as intelligence, are reviewed. The general finding that compression in time has a different effect upon the comprehensibility of connected discourse than upon word intelligibility is discussed, and a tentative explanation of this difference is offered. (63 ref.) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Frequency-shaped amplification changes the neural representation of speech with noise-induced hearing loss

Apoptosis is a mode of active cell death. We have examined whether 2-chloroethylethyl sulfide (CEES), a sulfur vesicating agent, triggers apoptosis as a cytotoxic mechanism. Incubation of thymocytes with CEES, resulted in an induction of apoptotic features of cell death. Treatment of cells with 100 microM CEES for 5 h increased DNA fragmentation to approximately 40% of control. The fragmentation of DNA was visualized by agarose gel electrophoresis. It showed ladder pattern of DNA fragmentation, which indicates internucleosomal cleavage of DNA. Further evidence of apoptosis was observed in morphological changes of nuclei by using the terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling (TUNEL) method. The percentage of TUNEL positive cells was dependent upon CEES concentrations. CEES induced the classical morphological features of apoptosis in nucleus. These features were accompanied by condensation of chromatin, which arranged in sharply declined clumps and fragmentation of nucleus. To study requirement for synthesis of new protein in CEES-induced apoptosis, we studied the effect of cycloheximide for apoptotic activity. This protein synthesis inhibitor did not suppress the CEES-induced apoptotic activity. Taken together, these results suggest that CEES-induced apoptosis as a cytotoxicmechanism and this process occurs independent of synthesis of new protein.     

Deficits in auditory temporal and spectral resolution in language-impaired children

Between 3 and 6 per cent of children who are otherwise unimpaired have extreme difficulties producing and understanding spoken language. This disorder is typically labelled specific language impairment. Children diagnosed with specific language impairment often have accompanying reading difficulties (dyslexia), but not all children with reading difficulties have specific language impairment. Some researchers claim that language impairment arises from failures specific to language or cognitive processing. Others hold that language impairment results from a more elemental problem that makes affected children unable to hear the acoustic distinctions among successive brief sounds in speech. Here we report the results of psychophysical tests employing simple tones and noises showing that children with specific language impairment have severe auditory perceptual deficits for brief but not long tones in particular sound contexts. Our data support the view that language difficulties result from problems in auditory perception, and provide further information about the nature of these perceptual problems that should contribute to improving the diagnosis and treatment of language impairment and related disorders.     

Working memory constraints on linear reasoning with spatial and temporal contents

The present article reports two experiments testing the use of working memory components during reasoning with temporal and spatial relations in four-term series problems. In the first experiment four groups of subjects performed reasoning tasks with temporal and with spatial contents either without (control) or with a secondary task (articulatory suppression, visuo-spatial suppression or central executive suppression). The second experiment tested the secondary task effects in a within-subjects design either on problems with a spatial content or on problems with a temporal content, and within each content domain either under conditions of self-paced or of fixed presentation of the premises. Both experiments found effects of all three secondary tasks on reasoning accuracy. This supports the hypothesis that the subjects construct spatial representations of the premise information with the support of visuo-spatial resources of working memory. The second experiment also showed that during premise intake, only visuo-spatial and central executive secondary tasks had an effect. The implications of the data for the working memory requirements of reasoning and for theories of linear reasoning are discussed.     

Factors governing speech reception benefits of adaptive linear filtering for listeners with sensorineural hearing loss

Adaptive linear filtering can improve effective speech-to-noise ratios by attenuating spectral regions with intense noise components to reduce the noise's spread of masking onto speech in neighboring regions. This mechanism was examined in static listening conditions for seven individuals with sensorineural hearing loss. Subjects were presented with nonsense syllables in an intense octave-band noise centered on 0.5, 1, or 2 kHz. The nonsense syllables were amplified to maximize. the articulation index; the noises were the same for all subjects. The processing consisted of applying frequency-selective attenuation to the speech-plus-noise with the goal of attenuating the frequency region containing the noise by various amounts. Consonant recognition scores and noise masking patterns were collected in all listening conditions. When compared with masking patterns obtained from normal-hearing subjects, all hearing-impaired subjects had higher masked thresholds at frequencies below, within, and above the masker band except for one subject who demonstrated additional masking above the masker only. Frequency-selective attenuation resulted in both increases and decreases in consonant recognition scores. Increases were associated with a release from upward spread of masking. Decreases were associated with applying too much attenuation such that speech energy within the masker band that was audible before processing was partially below threshold after processing. Fletcher's [Speech and Hearing in Communication (Van Nostrand, New York, 1953)] version of articulation theory (without modification) accounted for individual subject differences within the range of variability associated with the consonant recognition test in almost every instance. Hence, primary factors influencing speech reception benefits are characterized by articulation theory. Fletcher's theory appears well-suited to guide the design of control algorithms that will maximize speech recognition for individual listeners.     

Personality and linear representation of temporal location.

90 undergraduates completed 3 personality tests and a task in which Ss located 1 wk, 7 mo, 3 yrs, and 9 yrs past and future on 2 time lines labeled "birth to now" and "now to death." Data fit commonsense expectations that self-control, responsibility, and cognitive caution go along with subjective locations of the past and future close to the present and suggest that performance on a simple time line reflects some intimate relationships between temporal experience and personality. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Speech perception and speech comprehension investigations of pre-term newborns and high-risk neonates of pre-school age

The purpose of this study is to establish whether there is any connection between neonatal morbidity and speech perception and comprehension in children of pre-school age who have previously been treated as newborn infants in an intensive care unit. The test applied is a method invented in Hungary for the analysis of global hearing, speech perception and comprehension. The authors summarize the results of their follow-up studies of 52 children with respiratory disorders as newborns, some of whom were born as pre-term and some as full-term newborns with asphyxia. The children have been put into three groups according to their maturity and their birthweight. Newborns with hearing loss and mental retardation were excluded from this study. Of the various neonatal factors the results show: complications of delivery, birthweight, hypoxia, persistent ductus arteriosus, duration of ventilation and complications of respiratory treatment are found to be correlated to perception and comprehension. Incidences of poor achievement obtained in the most characteristic subtests have been compared among the different groups of newborns. The intelligence level of pre-school children is found to be closely correlated to speech perception and comprehension.     

Sentence comprehension in Alzheimer's disease: Effects of grammatical complexity, speech rate, and repetition.

Caregivers of patients diagnosed with Alzheimer's disease (AD) are often advised to modify their speech to facilitate the patients' sentence comprehension. Three common recommendations are to (a) speak in simple sentences, (b) speak slowly, and (c) repeat one's utterance, using the same words. These three speech modifications were experimentally manipulated in order to investigate their individual and combined effects on sentence comprehension in AD. Fifteen patients with mild to moderate AD and 20 healthy older persons were tested on a sentence comprehension task with sentences varying in terms of (a) degree of grammatical complexity, (b) rate of presentation (normal vs. slow), and (c) form of repetition (verbatim vs. paraphrase). The results indicated a significant decline in sentence comprehension for the AD group. Sentence comprehension improved, however, after the sentence was repeated in either verbatim or paraphrased form. However, the patients' comprehension did not improve for sentences presented at the slow speech rate. This pattern of results is explained vis-à-vis the patients' working memory loss. The findings challenge the appropriateness of several clinical recommendations. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Perception of temporal order in speech: The role of vowel transitions.

Presented 32 undergraduates with tape loops consisting of 4 sounds. 3 types of stimuli were used to construct tape loops. These consisted of (a) consonant noise removed from consonant-vowel (cv) syllables, (b) cv syllables composed of consonant noise and the first 75 msec of vowel (including vowel transitions), and (c) transitionless cv syllables composed of consonant noise and 75 msec of steady-state vowel. Ss judged the order of the 4 sounds in each tape loop. Tape loops composed of consonant noise were most difficult to order correctly. Transitionless syllables were more difficult to order correctly than normal cv syllables of the same duration. This result suggests that vowel transitions aid in maintaining the temporal order of speech sounds in normal speech. (French summary) (15 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The temporal and spatial features of event-related EEG spectral changes in 4 mental conditions

BACKGROUND: Neointimal fibroproliferative lesions after balloon angioplasty remain a major clinical problem, frequently leading to restenosis of initially successfully dilated coronary arteries. The cGMP-dependent protein kinase type I (cGMP-PK I) and its substrate vasodilator-stimulated phosphoprotein (VASP), molecular targets of the atrial natriuretic factor (ANF) and nitric oxide (NO) signalling pathways, are likely to be involved in various aspects of vascular wall regulation and restenosis formation. METHODS: To investigate the occurrence of cGMP-PK I and VASP in neointimal cells in situ, we performed immunohistochemistry and immunoblotting experiments on denuded rat carotid arteries. RESULTS: Although the soluble cGMP-PK I showed a homogeneous distribution throughout the neointima, VASP apparently was more concentrated in smooth muscle cells (SMCs) lining the artery lumen, possibly reflecting enhanced growth factor stimulation of luminal SMCs. The membrane-associated cGMP-PK type II could not be detected in both the non-injured vessel wall and the restenotic tissue. CONCLUSION: The presence of both cGMP-PK I and VASP, major regulators of the actin cytoskeleton and cell motility, in neointimal tissue suggest that this emerging signal transduction pathway could be a target for the regulation and control of restenosis.     

Reading and arithmetic in adolescents with autism spectrum disorders: Peaks and dips in attainment.

In describing academic attainment in autism spectrum disorders (ASD), results are typically reported at the group mean level. This may mask subgroups of individuals for whom academic achievement is incommensurate with intellectual ability. The authors tested the IQ, literacy, and mathematical abilities of a large group (N = 100) of adolescents (14–16 years old) with ASD. Seventy-three percent of the sample had at least one area of literacy or mathematical achievement that was highly discrepant (approximately 14 standard score points) from full-scale IQ (FSIQ). The authors focused on four subgroups with either word reading (“Reading Peak” and “Reading Dip”) or arithmetic (“Arithmetic Peak” and “Arithmetic Dip”) higher or lower than FSIQ. These subgroups were largely mutually exclusive and were characterized by distinct intellectual profiles. The largest was the “Arithmetic Peak” subgroup of participants, who presented with average intellectual ability alongside superior arithmetic skills and who were predominantly in a mainstream educational setting. Overall, the most pervasive profile was discrepantly poor reading comprehension, which associated with severity of social and communication difficulties. The high rate of uneven academic attainment in ASD has implications for educational practice. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Multidimensional scaling of synthetic musical timbre: Perception of spectral and temporal characteristics.

Investigated the perceptual correlates of acoustic parameters involved in musical timbre by examining judgements of timbre dissimilarity. Nine synthetic sounds were created, derived from crossing 3 levels of spectral and temporal parameters (number of harmonics and rise time). Two separate conditions were tested, 1 using single tones, the other using short melodies. 15 musically untrained 20–47 yr olds were presented with pairs of stimuli and judged dissimilarity on an 8-point scale. The spatial configuration resulting from multidimensional analysis of the data was best fit by a 3 dimensional model, with the 1st 2 dimensions accounting for most of the variance. The perceptual space derived from the analysis indicates that these 2 orthogonal dimensions corresponded closely to the spectral and temporal differences inherent to the stimuli. Similar results were obtained with both melodies and single tones. A 2nd experiment replicated the findings despite the introduction of random loudness variation. It is concluded that even musically unselected subjects are sensitive to spectral and temporal information in musical tones, and are able to use them independently in making perceptual judgements of musical timbre. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Interrelationships among warmth, genuineness, empathy, and temporal speech patterns in interpersonal interaction.

Paired 32 male and 32 female undergraduates, who were strangers to each other, into same-sex dyads. After a 45-min session of natural conversation in each dyad, Ss completed a questionnaire rating their conversational partners on empathy, warmth, and genuineness. Comparison of ratings by partners with ratings by independent Os did not correlate significantly. However, Os' ratings support the hypothesis that "switching pauses" (1 of the parameters of temporal congruence) would correlate significantly with ratings of warmth. Results show that the notion of switching-pause convergence as a reliable, objective measure of warmth in peer conversations is a valid one. (PsycINFO Database Record (c) 2010 APA, all rights reserved)