Auditory Temporal Cues Research Articles

The role of visual cues indicating onset times of target speech syllables in release from informational or energetic masking

• Listeners benefit from visually guided cues for the timing of syllables in noise. • Visual cues are redundant when there are auditory temporal cues from speech rhythm. • Visual cues are more effective at reducing informational than energetic masking. This study examined the effect of visual cues that provide the timing information of syllables in nonsense target sentences on the recognition of target speech against either a speech-spectrum noise masker or a two-talker masker. When the target sentences with normally regular rhythm were used (Experiment 1), visual cues indicating the onset times of the target-sentence syllables did not significantly improve target-speech recognition against either the speech-spectrum noise masker or the two-talker masker. On the other hand, recognition of the last (third) keyword in these normal rhythmic sentences was significantly better than that of the first keyword against the two-talker masker, but not the noise masker. This word-position-related speech-recognition improvement indicates a beneficial role of regular speech rhythm in release from informational masking due to the temporal prediction of target-sentence syllables. When artificially irregular rhythms were introduced into target sentences (Experiment 2), visual cues indicating syllable onset times significantly improved target-speech recognition against both types of masker. Moreover, the visual-cue-induced improvement in speech recognition against the two-talker masker was significantly larger than that against the speech-spectrum noise masker. The results of this study suggested that visual cues indicating target-syllable timing information improve target-speech recognition against competing maskers only when the temporal rhythmic regularity of target speech sentences is reduced.

The role of auditory temporal cues in the fluency of stuttering adults

ABSTRACT Purpose: to compare the frequency of disfluencies and speech rate in spontaneous speech and reading in adults with and without stuttering in non-altered and delayed auditory feedback (NAF, DAF). Methods: participants were 30 adults: 15 with Stuttering (Research Group - RG), and 15 without stuttering (Control Group - CG). The procedures were: audiological assessment and speech fluency evaluation in two listening conditions, normal and delayed auditory feedback (100 milliseconds delayed by Fono Tools software). Results: the DAF caused a significant improvement in the fluency of spontaneous speech in RG when compared to speech under NAF. The effect of DAF was different in CG, because it increased the common disfluencies and the total of disfluencies in spontaneous speech and reading, besides showing an increase in the frequency of stuttering-like disfluencies in reading. The intergroup analysis showed significant differences in the two speech tasks for the two listening conditions in the frequency of stuttering-like disfluencies and in the total of disfluencies, and in the flows of syllable and word-per-minute in the NAF. Conclusion: the results demonstrated that delayed auditory feedback promoted fluency in spontaneous speech of adults who stutter, without interfering in the speech rate. In non-stuttering adults an increase occurred in the number of common disfluencies and total of disfluencies as well as reduction of speech rate in spontaneous speech and reading.

Cross-Modal Distortion of Time Perception: Demerging the Effects of Observed and Performed Motion

Temporal information is often contained in multi-sensory stimuli, but it is currently unknown how the brain combines e.g. visual and auditory cues into a coherent percept of time. The existing studies of cross-modal time perception mainly support the “modality appropriateness hypothesis”, i.e. the domination of auditory temporal cues over visual ones because of the higher precision of audition for time perception. However, these studies suffer from methodical problems and conflicting results. We introduce a novel experimental paradigm to examine cross-modal time perception by combining an auditory time perception task with a visually guided motor task, requiring participants to follow an elliptic movement on a screen with a robotic manipulandum. We find that subjective duration is distorted according to the speed of visually observed movement: The faster the visual motion, the longer the perceived duration. In contrast, the actual execution of the arm movement does not contribute to this effect, but impairs discrimination performance by dual-task interference. We also show that additional training of the motor task attenuates the interference, but does not affect the distortion of subjective duration. The study demonstrates direct influence of visual motion on auditory temporal representations, which is independent of attentional modulation. At the same time, it provides causal support for the notion that time perception and continuous motor timing rely on separate mechanisms, a proposal that was formerly supported by correlational evidence only. The results constitute a counterexample to the modality appropriateness hypothesis and are best explained by Bayesian integration of modality-specific temporal information into a centralized “temporal hub”.

Neural correlates of auditory temporal-interval discrimination in cats

Auditory temporal cues are very important in the perception of speech; nevertheless, the neural correlates underlying even a simple temporal task, such as interval discrimination, remain unclear, mainly due to the lack of comparable data of psychophysical and electrophysiological experiments in the same species. To address this, we measured both behavioral and neural responses in cats. Cats’ ability to discriminate differences in sound intervals was tested by presenting two identical pure tone markers interrupted by intervals ranging from 10 to 320 ms duration. All three subjects could accurately discriminate tones of 80–320 ms interval from those of 10 ms interval (correct rate > 75%), but could not discriminate 20–40 ms interval from 10 ms interval. Neural responses to the same stimuli were recorded in the primary auditory cortex (A1) of three others awake cats. Consistent with previous studies, we found that the majority of A1 neurons showed a suppressed response to the second tone, and the amount of suppression generally increased with the decrease of intertone interval. Neurometric analysis revealed that neural responses could be used to discriminate the intertone interval, while discrimination performance was dependent on temporal precision to read the neural information. When spike activities were analyzed by 100 ms bin size, 80% of neurometric functions matched the cats’ psychometric function, suggesting a possible correlation between A1 activities and interval perception.

Audio–visual integration in temporal perception

In situations of audio–visual interaction, research has generally found that audition prevails over vision in temporal perception, while vision is dominant over audition for spatial perception. Modality appropriateness to a given task generally determines the direction of this inter-modality effect. However, we found a reverse effect in some situations where a change in the frequency of visual stimuli was associated with a perceived change in the frequency of auditory stimuli. In our experiment, 12 participants were asked to judge the change in the frequency of visual and auditory stimuli using a visual flicker and auditory flutter stimuli. In some conditions either the auditory or the visual information was ambiguous. In addition to confirming the expected finding that a change in the frequency of the auditory stimuli induced a perceived change in the frequency of the visual stimuli, we found a new phenomenon. When ambiguous auditory temporal cues were presented, the change in the frequency of the visual stimuli was associated with a perceived change in the frequency of the auditory stimuli. This suggests that cross-modal asymmetry effects are influenced by the reliability of visual and auditory information as well as modality appropriateness.

Auditory temporal processing in children with specific reading disability with and without attention deficit/hyperactivity disorder.

The auditory temporal deficit hypothesis predicts that children with specific reading disability (RD) will exhibit a deficit in the perception of auditory temporal cues in nonspeech stimuli. Tasks assessing perception of auditory temporal and nontemporal cues were administered to children with (a) RD without attention-deficit/hyperactivity disorder (RD/no-ADHD, n = 40), (b) ADHD alone (ADHD/no-RD, n = 33), (c) RD and ADHD (RD/ADHD, n = 36), and (d) no impairment (NI, n = 41). The presence of RD was associated with a specific deficit in detection of a tone onset time asynchrony, but no reduction in performance on other tasks assessing perception of temporal or nontemporal acoustic cues. The presence of ADHD was associated with a general reduction in performance across tasks. The pattern of results did not indicate a pervasive deficit in auditory temporal function in children with RD, but did suggest a possible sensitivity to backward masking in this group. Results also indicated that the comorbid presence of ADHD is a significant factor in the performance of children with RD on psychoacoustic tasks.

Brain Responses to Changes in Speech Sound Durations Differ Between Infants With and Without Familial Risk for Dyslexia

A specific learning disability, developmental dyslexia, is a language-based disorder that is shown to be strongly familial. Therefore, infants born to families with a history of the disorder are at an elevated risk for the disorder. However, little is known of the potential early markers of dyslexia. Here we report differences between 6-month-old infants with and without high risk of familial dyslexia in brain electrical activation generated by changes in the temporal structure of speech sounds, a critical cueing feature in speech. We measured event-related brain responses to consonant duration changes embedded in ata pseudowords applying an oddball paradigm, in which pseudoword tokens with varying /t/ duration were presented as frequent standard (80%) or as rare deviant stimuli (each 10%) with an interval of 610 msec between the stimuli. The infants at risk differ from control infants in both their initial responsiveness to sounds per se and in their change-detection responses dependent on the stimulus context. These results show that infants at risk due to a familial background of reading problems process auditory temporal cues of speech sounds differently from infants without such a risk even before they learn to speak.

Perception of Voice and Tone Onset Time Continua in Children with Dyslexia with and without Attention Deficit/Hyperactivity Disorder

Tasks assessing perception of a phonemic contrast based on voice onset time (VOT) and a nonspeech analog of a VOT contrast using tone onset time (TOT) were administered to children (ages 7.5 to 15.9 years) identified as having reading disability (RD; n = 21), attention deficit/hyperactivity disorder (ADHD; n = 22), comorbid RD and ADHD (n = 26), or no impairment (NI; n = 26). Children with RD, whether they had been identified as having ADHD or not, exhibited reduced perceptual skills on both tasks as indicated by shallower slopes on category labeling functions and reduced accuracy even at the endpoints of the series where cues are most salient. Correlations between performance on the VOT task and measures of single word decoding and phonemic awareness were significant only in the groups without ADHD. These findings suggest that (a) children with RD have difficulty in processing speech and nonspeech stimuli containing similar auditory temporal cues, (b) phoneme perception is related to phonemic awareness and decoding skills, and (c) the potential presence of ADHD needs to be taken into account in studies of perception in children with RD.