SEARCH · PubMed Health

Results for “Speech Perception”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 307 records · Page 17Linked to original sources

PubMed1997

Relative alpha desynchronization and synchronization during speech perception.

Brain processes elicited by speech were studied in 10 right-handed subjects by means of examining the desynchronization and synchronization of the 8-10 Hz and 10-12 Hz EEG alpha frequency bands. The subjects listened to an auditorily presented 5 min text passage. The text was presented both forward and backward. Listening to the text forward elicited alpha desynchronization in both of the frequency bands studied, whereas listening to the same text presented backward elicited synchronization in the 10-12 Hz frequency band only. Listening to the text forward elicited greater desynchronization than listening to the text backward. In the 10-12 Hz frequency band, listening to the text forward elicited desynchronization whereas listening to the same text backward elicited synchronization. This dissociation was not observed in the 8-10 Hz frequency band. The results suggest that the lower and upper alpha bands differ such that the 10-12 Hz frequency band exhibits reactivity to the presence of linguistic content while the 8-10 Hz band shows an unspecific response.

Acoustic Stimulation↗

PubMed1995

Verbal auditory closure and the speech perception in noise (SPIN) Test.

Ability to utilize auditory contextual information to facilitate speech-recognition verbal auditory closure is postulated to be a specific factor or primary mental ability, separable from general intelligence or other mental functions. This paper proposes that measurement of verbal auditory closure provides useful clinical information. Because the Speech Perception in Noise (SPIN). Test allows separate scores for understanding of sentences that contain contextual information and of those that do not, the SPIN Test provides a good measure of verbal auditory closure. Now that an authorized version of the revised SPIN Test is commercially available, it is appropriate to review published information about reported performance of different listener groups on this instrument and to propose additional research questions that deserve investigation.

Adolescent↗

PubMed1986

Auditory/visual speech perception by cochlear implant users and hearing aid wearers.

This study assessed the auditory/visual speech perception abilities of profoundly hearing-impaired subjects using the cochlear implant (CI) developed at the House Ear Institute with those of patients using traditional hearing aids (HA). Audio-video tape recordings of consonant-vowel-consonants (CVCs) consisting of: ten vowels in the context/mvm/, vowel-consonant-vowels (VCVs) consisting of twenty-four consonants in the context/ C /, and the CID Everyday Sentences were presented through auditory, visual, and auditory-visual modes. Subjects' verbal responses to the stimuli were transcribed by the experimenters. Statistical analyses of the data revealed significant differences for groups, stimuli, and conditions. Inspection of the subject's confusion matrices revealed that both groups used closed-bilabial, velar, dental, labial, and easy to see/hard to see features based on place of articulation in the visual mode. Salient features in the auditory mode for the CI group were duration, sonorancy, and some manner attributes, while the HA subjects used these features as well as sibilancy and voicing. Both groups integrated auditory and visual cues to improve scores in the auditory-visual condition. These findings have implications for future developments of auditory prostheses and auditory rehabilitation programs.

Adult↗

PubMed2006

Using a speech perception neural network computer simulation to contrast neuroanatomic versus neuromodulatory models of auditory hallucinations.

A number of studies suggest that schizophrenia may arise from overzealous pruning of synapses that are an extension of normal developmental pruning during adolescence. Moreover, there has been a long history of studies suggesting that this disorder arises from alterations in the dopaminergic neuromodulatory systems. In order to further assess and compare these two hypotheses, a computer simulation of some aspects of speech perception was developed utilizing a recurrent, backpropagation model of working memory previously reported by Elman . This system was found to produce spontaneous percepts simulating hallucinated speech when the working memory component either was excessively pruned or when neuronal responses were modulated to simulatea hyperdopaminergic system. These hallucinogenic systems also demonstrated disruptions in processing input information when "phonetic information" was degraded. The perceptual performance of these systems were compared to that of actual hallucinating patients and normal controls while tracking (repeating while simultaneously listening to) speech that was phonetically degraded. We found that the neural network simulation producing the best match to speech tracking performance of human hallucinators was an overpruned system with compensatory hypodopaminergic adjustments. These data suggest that the primary pathophysiology of schizophrenia arises from curtailed connectivity in working memory systems and that dopaminergic alterations reflect secondary compensatory adjustments.

Adolescent↗

PubMed1983

Evaluation and integration of visual and auditory information in speech perception.

Three experiments were carried out to investigate the evaluation and integration of visual and auditory information in speech perception. In the first two experiments, subjects identified /ba/ or /da/ speech events consisting of high-quality synthetic syllables ranging from /ba/ to /da/ combined with a videotaped /ba/ or /da/ or neutral articulation. Although subjects were specifically instructed to report what they heard, visual articulation made a large contribution to identification. The tests of quantitative models provide evidence for the integration of continuous and independent, as opposed to discrete or nonindependent, sources of information. The reaction times for identification were primarily correlated with the perceived ambiguity of the speech event. In a third experiment, the speech events were identified with an unconstrained set of response alternatives. In addition to /ba/ and /da/ responses, the /bda/ and /tha/ responses were well described by a combination of continuous and independent features. This body of results provides strong evidence for a fuzzy logical model of perceptual recognition.

Hearing↗

PubMed2005

Speech perception with mono- and quadrupolar electrode configurations: a crossover study.

OBJECTIVE: To study the effect of two multipolar electrode configurations on speech perception, pitch perception, and the intracochlear electrical field. STUDY DESIGN: Crossover design; within subject. SETTING: Tertiary referral center. PATIENTS: Eight experienced adult cochlear implant users. INTERVENTION: Each subject used each of three experimental processors for 3 weeks. The following processors were compared that differed only in electrode configuration: 1) monopolar; 2) hybrid quadrupolar, in which half of the current returned to the extracochlear reference electrode and half to two electrodes immediately to the left and right of the active electrode; and 3) flat tripolar +2, which directed all the current to four reference electrodes (two on each side), separated from the active electrode by two inactive electrodes. All the processors used the standard Advanced Bionics HiRes speech-processing strategy, 12 channels, 1,220 pulses per second per channel, and with a pulse width of 33 (micros/phase). RESULTS: The monopolar processors had the largest stimulation efficiency and the smallest dynamic range in linear current units. The reverse was true of flat tripolar +2 processor, whereas the hybrid quadrupolar processor fell in between. Insufficient loudness growth prevented the use of the flat tripolar +2 processor in three subjects. Word recognition did not differ between the clinically used 16-channel monopolar processor and the experimental monopolar processor, regardless of the differences in the number of channels, pulse rate, and duration of experience. Word recognition with the flat tripolar +2 processor was significantly poorer than with the monopolar and hybrid quadrupolar processors; monopolar and quadrupolar processors did not differ. There was no significant interaction between processor type and competing noise type (stationary or fluctuating), but performance at the higher level of fluctuating noise was best with the hybrid quadrupolar processor in almost all the subjects. Pitch scaling showed ceiling performance in five subjects and differed between processors in the two other subjects with imperfect tonotopy. Intracochlear current spread was considerable with the monopolar configuration; it was reduced with the hybrid quadrupolar configuration and virtually absent beyond the active electrodes with the tripolar configuration. CONCLUSION: More confined configurations reduced the longitudinal width of the electrical field, which was expected to enhance channel separation, but no improvement in word recognition was found. More research is needed to test confined configurations that have enhanced efficiency and to evaluate the fundamental effects of configuration on channel discriminability.

Acoustic Stimulation↗

PubMed2002

Effects of variation in emotional tone of voice on speech perception.

The effects of variation from stimulus to stimulus in emotional tone of voice on speech perception were examined through a series of perceptual experiments. Stimuli were recorded from human speakers who produced utterances in tones of voice designed to convey affective information. Then, stimuli varying in talker voice and emotional tone were presented to listeners for perceptual matching and classification. The results showed that both intertalker variation in talker voice and intratalker variation in emotional tone had a negative effect on perceptual performance. The results suggest that sources of variation in the speech signal that affect the spectral/temporal properties of speech (i.e., talker voice, speech rate, emotional tone) may be treated differently than sources of variation that do not affect these properties (i.e., vocal amplitude).

Affect↗

PubMed1999

Acoustic-phonetic approach toward understanding neural processes and speech perception.

This review paper describes an "acoustic-phonetic" experimental approach aimed at understanding normal and abnormal speech perception processes from both a behavioral and an electrophysiologic perspective. First, we consider the relevant acoustic characteristics of speech and identify a set of acoustic-phonetic classes that represent the parameters most important for making an acoustic signal sound like speech. Second, we review what is known about the neurophysiologic representation of acoustic-phonetic speech parameters in animal and human subjects. Third, we describe how an acoustic-phonetic approach has been useful in understanding the biologic basis of some auditory learning problems in children and in characterizing the behavioral and neurophysiologic changes resulting from speech-sound training. Finally, we discuss these findings and how they may expand the diagnostic and rehabilitative repertoire of practicing audiologists.

Auditory Cortex↗

PubMed2000

Visual and audiovisual speech perception with color and gray-scale facial images.

Research has shown that auditory speech recognition is influenced by the appearance of a talker's face, but the actual nature of this visual information has yet to be established. Here, we report three experiments that investigated visual and audiovisual speech recognition using color, gray-scale, and point-light talking faces (which allowed comparison with the influence of isolated kinematic information). Auditory and visual forms of the syllables /ba/, /bi/, /ga/, /gi/, /va/, and /vi/ were used to produce auditory, visual, congruent, and incongruent audiovisual speech stimuli. Visual speech identification and visual influences on identifying the auditory components of congruent and incongruent audiovisual speech were identical for color and gray-scale faces and were much greater than for point-light faces. These results indicate that luminance, rather than color, underlies visual and audiovisual speech perception and that this information is more than the kinematic information provided by point-light faces. Implications for processing visual and audiovisual speech are discussed.

Adolescent↗

PubMed1993

Impaired speech perception in noise in patients with a normal audiogram.

Patients with normal hearing acuity but complaining of impaired speech perception in noisy conditions were submitted to a test battery including the measurement of the speech reception threshold in noise and central auditory tests. In 95% of the cases the complaint was corroborated by an abnormal speech reception threshold (SRT) in noise. Central auditory tests were abnormal in 65% of the patients. Auditory brainstem-evoked potentials were measured in some of these patients and showed normal results in almost all cases. No specific relationship could be found between an elevated SRT in noise or an abnormal central test result.

Acoustic Stimulation↗

PubMed2004

Allophonic mode of speech perception in dyslexia.

Perceptual discrimination between speech sounds belonging to different phoneme categories is better than that between sounds falling within the same category. This property, known as "categorical perception," is weaker in children affected by dyslexia. Categorical perception develops from the predispositions of newborns for discriminating all potential phoneme categories in the world's languages. Predispositions that are not relevant for phoneme perception in the ambient language are usually deactivated during early childhood. However, the current study shows that dyslexic children maintain a higher sensitivity to phonemic distinctions irrelevant in their linguistic environment. This suggests that dyslexic children use an allophonic mode of speech perception that, although without straightforward consequences for oral communication, has obvious implications for the acquisition of alphabetic writing. Allophonic perception specifically affects the mapping between graphemes and phonemes, contrary to other manifestations of dyslexia, and may be a core deficit.

Case-Control Studies↗

PubMed1985

Phonetic speech perception deficits in dyslexia.

Adult developmental dyslexics showed deficits in the identification of the vowels of English when the sole acoustic cues were steady-state formant frequency patterns. Deficits in the identification of place of articulation of the English stop-consonants [b], [d] and [g] in syllable-initial position were also observed. The average consonantal error rate was 22%. These error rates are significantly different from those of nondyslexic control groups (p less than .01). No single deficit characterized the entire group of dyslexic subjects. The pattern of errors with respect to place of articulation also varied for different groups of subjects. Three dyslexics have high vowel error rates and low consonantal error rates. The data are consistent with the premise that dyslexic subjects may have different perceptual deficits rather than a general auditory deficit involving the rate at which they can process perceptual information. The clinical histories of the present subjects suggest genetic transmission of these speech perception deficits. The presence of genetic variation in the biological substrate relevant to the perception of human speech should be further explored.

Adolescent↗

PubMedDate not supplied

[Speech perception in cochlear implant users: two programming situations].

BACKGROUND: In order to shorten the programming process of cochlear implanted (CI) children it is possible to establish the T level (threshold level) as being 10% of the C level (most comfortable level). AIM: To compare the results of speech perception tests using the map of the real thresholds levels and the map corresponding to 10% of the C level. MRTHODS: A list of monosyllables and sentences were used with 30 CI individuals in two programming situations. RESULTS: no difference was found between the results in the speech tests in the two programming situations. CONCLUSION: The use of the map with the T level corresponding to 10% of the C level can be an option to program young children, especially for those who do not respond to the investigation of the real T levels.

Adolescent↗

PubMed2003

Auditory-visual speech perception examined by fMRI and PET.

Cross-modal binding in auditory-visual speech perception was investigated by using the McGurk effect, a phenomenon in which hearing is altered by incongruent visual mouth movements. We used functional magnetic resonance imaging (fMRI) and positron emission tomography (PET). In each experiment, the subjects were asked to identify spoken syllables ('ba', 'da', 'ga') presented auditorily, visually, or audiovisually (incongruent stimuli). For the auditory component of the stimuli, there were two conditions of intelligibility (High versus Low) as determined by the signal-to-noise (SN) ratio. The control task was visual talker identification of still faces. In the Low intelligibility condition in which the auditory component of the speech was harder to hear, the visual influence was much stronger. Brain imaging data showed bilateral activations specific to the unimodal auditory stimuli (in the temporal cortex) and visual stimuli (in the MT/V5). For the bimodal audiovisual stimuli, activation in the left temporal cortex extended more posteriorly toward the visual-specific area in the Low intelligibility condition. The direct comparison between the Low and High audiovisual conditions showed increased activations in the posterior part of the left superior temporal sulcus (STS), indicating its relationship with the stronger visual influence. It was discussed that this region is likely to be involved in cross-modal binding of auditory-visual speech.

Acoustic Stimulation↗

PubMed1991

Signal detection and speech perception with level-dependent hearing protectors.

An experiment was conducted to investigate signal detection and speech perception with level-dependent hearing protectors. Twenty normal-hearing young adults participated in the first phase of this program, the ultimate objective of which was an assessment of the effect of hearing loss. For each subject, measurements were made of the detection of one-third octave noise bands centered at 500, 1000, 2000 and 4000 Hz, consonant discrimination, and word recognition. Performance on these tests was evaluated in quiet and in a background of 75 dB SPL cable swager noise, with the ears unoccluded and protected with four different muffs. The devices selected were the E-A-R 9000 and BILSOM 2390 and their conventional level-independent counterparts, the E-A-R 3000 and BILSOM 2315. The results indicated that signal detection in noise generally remained the same or was slightly enhanced when the protectors were worn. For consonant discrimination, there were no differences among the various protectors in quiet, while in noise the wearing of the BILSOM 2390 resulted in a significant decrement in the intelligibility of the initial consonant. For word recognition, the BILSOM 2390 resulted in an advantage in quiet, particularly for sentences with low contextual cues. The reverse effect was true in noise. The results obtained for the E-A-R 9000 were similar to those for the two conventional HPDs.

Acoustics↗

PubMed1989

The role of visual information in the processing of place and manner features in speech perception.

Visual information provided by a talker's mouth movements can influence the perception of certain speech features. Thus, the "McGurk effect" shows that when the syllable (bi) is presented audibly, in synchrony with the syllable (gi), as it is presented visually, a person perceives the talker as saying (di). Moreover, studies have shown that interactions occur between place and voicing features in phonetic perception, when information is presented audibly. In our first experiment, we asked whether feature interactions occur when place information is specificed by a combination of auditory and visual information. Members of an auditory continuum ranging from (ibi) to (ipi) were paired with a video display of a talker saying (igi). The auditory tokens were heard as ranging from (ibi) to (ipi), but the auditory-visual tokens were perceived as ranging from (idi) to (iti). The results demonstrated that the voicing boundary for the auditory-visual tokens was located at a significantly longer VOT value than the voicing boundary for the auditory continuum presented without the visual information. These results demonstrate that place-voice interactions are not limited to situations in which place information is specified audibly.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1990

Selective hearing in the aged with regard to speech perception in quiet and in noise.

Most listening environments contain some noise which is mixed up with the speech. The effects of noise on speech perception depend on the parameters of the noise (long term spectrum, fluctuations of the intensity in time and average intensity relative to the intensity of speech) and on the speech material (sentences, monosyllables, CV-, CVC-, VC-syllables). The most effective at masking are noises with spectra similar to the speech spectrum, such as the speech simulating noise (CCITT-noise) or cocktail-party-noise. The cocktail-party situation is judged to be a difficult communication situation not only by the hearing impaired but also by patients with presbycusis. We examined different age-dependent changes of the speech discrimination in noise ability. Using sentences and CV-syllables (rhyme test) the critical signal-to-noise ratios (S/N-dB) for a speech discrimination of 35%-45% were investigated for monaural and binaural noise representations for different age groups. The results are compared to several types of hearing loss and to those of similar studies in literature. The data of this study prove that hearing impaired and elderly patients are greatly affected by noise. While younger patients with moderate high-tone hearing loss may profit from a special hearing aid device with an integrated noise suppression-system, an improvement of speech discrimination in noise for the elderly can be achieved only by enhancing the signal-to-noise ratio by more than 10 dB. This is possibly because of the reduced capacity for frequency-, intensity- and time-resolution in the peripheral and central pathways of the hearing organ of the aged.

Adult↗

PubMed1999

Attention to facial regions in segmental and prosodic visual speech perception tasks.

Two experiments were conducted to test the hypothesis that visual information related to segmental versus prosodic aspects of speech is distributed differently on the face of the talker. In the first experiment, eye gaze was monitored for 12 observers with normal hearing. Participants made decisions about segmental and prosodic categories for utterances presented without sound. The first experiment found that observers spend more time looking at and direct more gazes toward the upper part of the talker's face in making decisions about intonation patterns than about the words being spoken. The second experiment tested the Gaze Direction Assumption underlying Experiment 1--that is, that people direct their gaze to the stimulus region containing information required for their task. In this experiment, 18 observers with normal hearing made decisions about segmental and prosodic categories under conditions in which face motion was restricted to selected areas of the face. The results indicate that information in the upper part of the talker's face is more critical for intonation pattern decisions than for decisions about word segments or primary sentence stress, thus supporting the Gaze Direction Assumption. Visual speech perception proficiency requires learning where to direct visual attention for cues related to different aspects of speech.

Adult↗