Auditory White Noise Research Articles

A Novel Approach to Sensorimotor Skill Acquisition Utilizing Sensory Substitution: A Driving Simulation Study

The aim of this study is to demonstrate the potential of sensory substitution/augmentation (SS/A) techniques for driver assistance systems in a simulated driving environment. Using a group-comparison design, we examined lane-keeping skill acquisition in a driving simulator that can provide information regarding vehicle lateral position by changing the binaural balance of auditory white noise delivered to the driver. Consequently, lane-keeping accuracy was significantly degraded when the lower visual scene (proximal part of the road) was occluded, suggesting it conveyed critical visual information necessary for lane keeping. After 40 minutes of training with auditory cueing of vehicle lateral position, lane-keeping accuracy returned to the baseline (normal driving) level. This indicates that auditory cueing can compensate for the loss of visual information. Taken together, our data suggest that auditory cueing of vehicle lateral position is sufficient for lane-keeping skill acquisition and that SS/A techniques can potentially be used for the development of driver assistance systems, particularly for situations where immediate time-sensitive actions are required in response to rapidly changing sensory information. Although this study is the first to apply SS/A techniques to driver assistance, further studies are however required to establish the generalizability of the findings to real-world settings.

White noise facilitates new-word learning from context

Listening to white noise may facilitate cognitive performance, including new word learning, for some individuals. This study investigated whether auditory white noise facilitates the learning of novel written words from context in healthy young adults. Sixty-nine participants were required to determine the meaning of novel words placed within sentence contexts during a silent reading task. Learning was performed either with or without white noise, and recognition of novel word meanings was tested immediately after learning and after a short delay. Immediate recognition accuracy for learned novel word meanings was higher in the noise group relative to the no noise group, however this effect was no longer evident at the delayed recognition test. These findings suggest that white noise has the capacity to facilitate meaning acquisition from context, however further research is needed to clarify its capacity to improve longer-term retention of meaning.

Auditory White Noise Affects Left/Right Visual Working Memory in an Opposite Pattern.

Adding auditory white noise (WN) to the environment has been considered to be a promising way to enhance the memory performance of children with attention deficit/hyperactivity disorder (ADHD) but disrupt that of non-ADHD children. To explore the exact mechanism behind WN benefits, we did a bilateral color-memory task with different WN conditions. A bilateral color-square array was displayed on one display. Only one side colors were asked to be remembered in a trial. Our experiment found that the memory accuracy of left visual memory was improved with WN, especially when WN was displayed via left earphone at encoding and maintenance periods. However, the right visual memory showed a reduced performance tendency with WN. Thus, the WN affects left/right visual working memory in an opposite pattern. Using time-frequency analysis, we found an enhanced lower-alpha activity over the left occipitotemporal lobe. We conclude that the induced lower-alpha activity at the left occipitotemporal lobe might be helpful to inhibit information processing of left hemisphere.

Effects of white noise duration on somatosensory event-related potentials.

Exposure to auditory white noise has been shown to facilitate cognitive function. This phenomenon is called stochastic resonance. The present study examined the effects of white noise duration on behavioral data [reaction time (RT), the SD of RT, and error rates] and the N140 and P300 components of event-related potentials in somatosensory Go/No-go paradigms. A Go or No-go stimulus was presented to the second or fifth digit of the left hand, respectively, at the same probability. Before recording event-related potentials, participants heard three different white noise durations (1, 3, and 5-min conditions), and performed somatosensory Go/No-go paradigms while listening to white noise. RT was significantly shorter under the 5 and 3-min conditions than under the 1-min condition, whereas SD of RT and error rates remained unchanged. The peak latency of Go-P300 was the shortest under the 5-min condition. White noise did not affect the peak latency of N140 or the peak amplitude of N140 or P300. Our results suggest that 5-min white noise exposure accelerated RT and the latency of Go-P300, reflecting changes in the neural activation of response execution processing.

Effects of stimulus intensity and auditory white noise on human somatosensory cognitive processing: a study using event-related potentials

Exposure to auditory white noise has been shown to facilitate cognitive function. This phenomenon is often called stochastic resonance, and a moderate amount of auditory noise has been suggested to benefit individuals in hypodopaminergic states. Previous studies using psychophysic methods reported that stochastic resonance was sensitive to stimulus intensity; however, the relationship between neural activities elicited by different stimulus intensities and auditory white noise has not yet been clarified Thus, the present study aimed to investigate the effects of stimulus intensity (Experiment 1) and auditory white noise (Experiment 2) on behavioral data (reaction time (RT), the standard deviation of RT, and error rates), and the N140 and P300 components of event-related potentials (ERPs) in somatosensory Go/No-go paradigms. The subjects had to respond to the somatosensory stimuli by pressing a button with their right thumb only after presentation of the Go stimulus. In Experiment 1 with four different stimulus intensity levels, the peak latencies of N140 and P300 became shorter, and the peak amplitudes of N140 and P300 were enhanced with increases in stimulus intensity. In Experiment 2 with weak and mild intensities under auditory white noise and control conditions, the amplitudes of Go-P300 and No-go-P300 were enhanced by white noise, irrespective of weak and mild intensities, during Go/No-go paradigms. Auditory white noise did not significantly affect the amplitude of N140 or the latencies of N140 and P300. These results suggest the presence of a characteristic cross-modal stochastic resonance in neural substrates utilizing somatosensory ERPs.

The impact of auditory white noise on semantic priming

It has been proposed that white noise can improve cognitive performance for some individuals, particularly those with lower attention, and that this effect may be mediated by dopaminergic circuitry. Given existing evidence that semantic priming is modulated by dopamine, this study investigated whether white noise can facilitate semantic priming. Seventy-eight adults completed an auditory semantic priming task with and without white noise, at either a short or long inter-stimulus interval (ISI). Measures of both direct and indirect semantic priming were examined. Analysis of the results revealed significant direct and indirect priming effects at each ISI in noise and silence, however noise significantly reduced the magnitude of indirect priming. Analyses of subgroups with higher versus lower attention revealed a reduction to indirect priming in noise relative to silence for participants with lower executive and orienting attention. These findings suggest that white noise focuses automatic spreading activation, which may be driven by modulation of dopaminergic circuitry.

Selective Attention Compensates Detrimental Effect of Auditory Noise on Performance in Posner Experiment

Environmental noise has a degrading effect on individual’s capacity to pay attention. In this paper, we revealed that the individual’s impaired performance under noise can be counterpoised by recollecting and recalling his attention. We studied the effect of auditory white noise on individual’s performance in Posner experiment; and examined if actively reorienting the individual’s attention to stimuli would mitigate the effects of auditory noise. Our subjects, ten undergraduate students, participated in the classical Posner experiment, while auditory white noise was being played for them through earphone. We varied the intensity of the auditory noise and studied subject’s performance in three conditions: neutral, valid cued, and invalid cued trials. Our results showed that the presence of auditory noise degraded subject’s performance in neutral trials. However, subject’s performance was not affected by auditory noise in valid cued trials.

Effects of white noise on event-related potentials in somatosensory Go/No-go paradigms.

Exposure to auditory white noise has been shown to facilitate human cognitive function. This phenomenon is termed stochastic resonance, and a moderate amount of auditory noise has been suggested to benefit individuals in hypodopaminergic states. The present study investigated the effects of white noise on the N140 and P300 components of event-related potentials in somatosensory Go/No-go paradigms. A Go or No-go stimulus was presented to the second or fifth digit of the left hand, respectively, at the same probability. Participants performed somatosensory Go/No-go paradigms while hearing three different white noise levels (45, 55, and 65 dB conditions). The peak amplitudes of Go-P300 and No-go-P300 in ERP waveforms were significantly larger under 55 dB than 45 and 65 dB conditions. White noise did not affect the peak latency of N140 or P300, or the peak amplitude of N140. Behavioral data for the reaction time, SD of reaction time, and error rates showed the absence of an effect by white noise. This is the first event-related potential study to show that exposure to auditory white noise at 55 dB enhanced the amplitude of P300 during Go/No-go paradigms, reflecting changes in the neural activation of response execution and inhibition processing.

Auditory white noise reduces age-related fluctuations in balance

Fall prevention technologies have the potential to improve the lives of older adults. Because of the multisensory nature of human balance control, sensory therapies, including some involving tactile and auditory noise, are being explored that might reduce increased balance variability due to typical age-related sensory declines. Auditory white noise has previously been shown to reduce postural sway variability in healthy young adults. In the present experiment, we examined this treatment in young adults and typically aging older adults. We measured postural sway of healthy young adults and adults over the age of 65 years during silence and auditory white noise, with and without vision. Our results show reduced postural sway variability in young and older adults with auditory noise, even in the absence of vision. We show that vision and noise can reduce sway variability for both feedback-based and exploratory balance processes. In addition, we show changes with auditory noise in nonlinear patterns of sway in older adults that reflect what is more typical of young adults, and these changes did not interfere with the typical random walk behavior of sway. Our results suggest that auditory noise might be valuable for therapeutic and rehabilitative purposes in older adults with typical age-related balance variability.

Self-Rated Attentiveness Interacts with Transcranial Direct Current Stimulation and Noise Stimulation in Reaction Time in a Go/No-Go Task.

Previous research has found that stimulating inattentive people with auditory white noise induces enhancement in cognitive performance. This enhancement is believed to occur due to a statistical phenomenon called stochastic resonance, where noise increases the probability of a signal passing the firing threshold in the neural cells. Here we investigate whether people with low attentiveness benefit to a larger extent than attentive people from stimulation by auditory white noise and transcranial direct current stimulation (tDCS). The results show, for both auditory noise and tDCS stimulation, that the changes in performance relative to nonstimulation correlate with the degree of attentiveness in a Go/No-Go task, but not in a N-back task. These results suggest that the benefit of tDCS may interact with inattentiveness.

Auditory white noise reduces postural fluctuations even in the absence of vision.

The contributions of somatosensory, vestibular, and visual feedback to balance control are well documented, but the influence of auditory information, especially acoustic noise, on balance is less clear. Because somatosensory noise has been shown to reduce postural sway, we hypothesized that noise from the auditory modality might have a similar effect. Given that the nervous system uses noise to optimize signal transfer, adding mechanical or auditory noise should lead to increased feedback about sensory frames of reference used in balance control. In the present experiment, postural sway was analyzed in healthy young adults where they were presented with continuous white noise, in the presence and absence of visual information. Our results show reduced postural sway variability (as indexed by the body's center of pressure) in the presence of auditory noise, even when visual information was not present. Nonlinear time series analysis revealed that auditory noise has an additive effect, independent of vision, on postural stability. Further analysis revealed that auditory noise reduced postural sway variability in both low- and high-frequency regimes (> or <0.3Hz) of sway, suggesting that both spontaneous and feedback-driven aspects of postural fluctuations were influenced by acoustic noise. Our results support the idea that auditory white noise reduces postural sway, suggesting that auditory noise might be used for therapeutic and rehabilitation purposes in older individuals and those with balance disorders.

Brain networks engaged in audiovisual integration during speech perception revealed by persistent homology-based network filtration.

The human brain naturally integrates audiovisual information to improve speech perception. However, in noisy environments, understanding speech is difficult and may require much effort. Although the brain network is supposed to be engaged in speech perception, it is unclear how speech-related brain regions are connected during natural bimodal audiovisual or unimodal speech perception with counterpart irrelevant noise. To investigate the topological changes of speech-related brain networks at all possible thresholds, we used a persistent homological framework through hierarchical clustering, such as single linkage distance, to analyze the connected component of the functional network during speech perception using functional magnetic resonance imaging. For speech perception, bimodal (audio-visual speech cue) or unimodal speech cues with counterpart irrelevant noise (auditory white-noise or visual gum-chewing) were delivered to 15 subjects. In terms of positive relationship, similar connected components were observed in bimodal and unimodal speech conditions during filtration. However, during speech perception by congruent audiovisual stimuli, the tighter couplings of left anterior temporal gyrus-anterior insula component and right premotor-visual components were observed than auditory or visual speech cue conditions, respectively. Interestingly, visual speech is perceived under white noise by tight negative coupling in the left inferior frontal region-right anterior cingulate, left anterior insula, and bilateral visual regions, including right middle temporal gyrus, right fusiform components. In conclusion, the speech brain network is tightly positively or negatively connected, and can reflect efficient or effortful processes during natural audiovisual integration or lip-reading, respectively, in speech perception.

Expression of freezing and fear-potentiated startle during sustained fear in mice.

Fear-potentiated acoustic startle paradigms have been used to investigate phasic and sustained components of conditioned fear in rats and humans. This study describes a novel training protocol to assess phasic and sustained fear in freely behaving C57BL/6J mice, using freezing and/or fear-potentiated startle as measures of fear, thereby, if needed, allowing in vivo application of various techniques, such as optogenetics, electrophysiology and pharmacological intervention, in freely behaving animals. An auditory Pavlovian fear conditioning paradigm, with pseudo-randomized conditioned-unconditioned stimulus presentations at various durations, is combined with repetitive brief auditory white noise burst presentations during fear memory retrieval 24 h after fear conditioning. Major findings are that (1) a motion sensitive platform built on mechano-electrical transducers enables measurement of startle responses in freely behaving mice, (2) absence or presence of startle stimuli during retrieval as well as unpredictability of a given threat determine phasic and sustained fear response profiles and (3) both freezing and startle responses indicate phasic and sustained components of behavioral fear, with sustained freezing reflecting unpredictability of conditioned stimulus (CS)/unconditioned stimulus (US) pairings. This paradigm and available genetically modified mouse lines will pave the way for investigation of the molecular and neural mechanisms relating to the transition from phasic to sustained fear.

Different effects of adding white noise on cognitive performance of sub-, normal and super-attentive school children.

ObjectivesNoise often has detrimental effects on performance. However, because of the phenomenon of stochastic resonance (SR), auditory white noise (WN) can alter the “signal to noise” ratio and improve performance. The Moderate Brain Arousal (MBA) model postulates different levels of internal “neural noise” in individuals with different attentional capacities. This in turn determines the particular WN level most beneficial in each individual case–with one level of WN facilitating poor attenders but hindering super-attentive children. The objective of the present study is to find out if added WN affects cognitive performance differently in children that differ in attention ability.MethodsParticipants were teacher-rated super- (N = 25); normal- (N = 29) and sub-attentive (N = 36) children (aged 8 to 10 years). Two non-executive function (EF) tasks (a verbal episodic recall task and a delayed verbal recognition task) and two EF tasks (a visuo-spatial working memory test and a Go-NoGo task) were performed under three WN levels. The non-WN condition was only used to control for potential differences in background noise in the group testing situations.ResultsThere were different effects of WN on performance in the three groups-adding moderate WN worsened the performance of super-attentive children for both task types and improved EF performance in sub-attentive children. The normal-attentive children’s performance was unaffected by WN exposure. The shift from moderate to high levels of WN had little further effect on performance in any group.SignificanceThe predicted differential effect of WN on performance was confirmed. However, the failure to find evidence for an inverted U function challenges current theories. Alternative explanations are discussed. We propose that WN therapy should be further investigated as a possible non-pharmacological treatment for inattention.

White Noise Improves Learning by Modulating Activity in Dopaminergic Midbrain Regions and Right Superior Temporal Sulcus

In neural systems, information processing can be facilitated by adding an optimal level of white noise. Although this phenomenon, the so-called stochastic resonance, has traditionally been linked with perception, recent evidence indicates that white noise may also exert positive effects on cognitive functions, such as learning and memory. The underlying neural mechanisms, however, remain unclear. Here, on the basis of recent theories, we tested the hypothesis that auditory white noise, when presented during the encoding of scene images, enhances subsequent recognition memory performance and modulates activity within the dopaminergic midbrain (i.e., substantia nigra/ventral tegmental area, SN/VTA). Indeed, in a behavioral experiment, we can show in healthy humans that auditory white noise-but not control sounds, such as a sinus tone-slightly improves recognition memory. In an fMRI experiment, white noise selectively enhances stimulus-driven phasic activity in the SN/VTA and auditory cortex. Moreover, it induces stronger connectivity between SN/VTA and right STS, which, in addition, exhibited a positive correlation with subsequent memory improvement by white noise. Our results suggest that the beneficial effects of auditory white noise on learning depend on dopaminergic neuromodulation and enhanced connectivity between midbrain regions and the STS-a key player in attention modulation. Moreover, they indicate that white noise could be particularly useful to facilitate learning in conditions where changes of the mesolimbic system are causally related to memory deficits including healthy and pathological aging.

Electrocorticography Reveals Enhanced Visual Cortex Responses to Visual Speech

Human speech contains both auditory and visual components, processed by their respective sensory cortices. We test a simple model in which task-relevant speech information is enhanced during cortical processing. Visual speech is most important when the auditory component is uninformative. Therefore, the model predicts that visual cortex responses should be enhanced to visual-only (V) speech compared with audiovisual (AV) speech. We recorded neuronal activity as patients perceived auditory-only (A), V, and AV speech. Visual cortex showed strong increases in high-gamma band power and strong decreases in alpha-band power to V and AV speech. Consistent with the model prediction, gamma-band increases and alpha-band decreases were stronger for V speech. The model predicts that the uninformative nature of the auditory component (not simply its absence) is the critical factor, a prediction we tested in a second experiment in which visual speech was paired with auditory white noise. As predicted, visual speech with auditory noise showed enhanced visual cortex responses relative to AV speech. An examination of the anatomical locus of the effects showed that all visual areas, including primary visual cortex, showed enhanced responses. Visual cortex responses to speech are enhanced under circumstances when visual information is most important for comprehension.

The temporal resolution of binding brightness and loudness in dynamic random sequences

Purpose. This study investigated the ways in which observers can combine dynamic visual and auditory information. Method. The stimuli were composed of gray disks accompanied by simultaneous bursts of auditory white noise. Three levels of disk brightness and of noise loudness were used to produce 9 different types of audiovisual tokens. On a given trial, 18 tokens (83ms per token) drawn from these 9 token types were presented in random order. Different conditions required participants to try to classify stimulus sequences using various target filters that gave differential weight to the 9 audiovisual token types. In each condition, a probit model was used to measure the attention filter achieved by the participant (the impact exerted on the observer’s judgments by each of the 9 token-types). The model also included terms reflecting potential non-simultaneous "misbindings" across time of auditory and visual components. Results. Participants demonstrated a high degree of strategic flexibility in achieving attention filters that varied widely across tasks, but these filters often deviated strongly from the corresponding target filters. Model fits revealed that misbindings of auditory and visual components that were 83 ms apart influenced judgments with half the strength of simultaneous components. Components that were 167 ms apart did not misbind. Conclusions. The temporal resolution of the binding achieved with these stimuli is higher than is found in tasks requiring the observer to judge the phase with which an alternating pair of visual stimuli matches up with an alternating pair of auditory stimuli (Fujisaki & Nishida, 2010). In correlating loudness and brightness, the space of attention filters that participants are able to achieve is at least three dimensional. Citation: Fujisaki, W & Nishida, S (2010). A common perceptual temporal limit of binding synchronous inputs across different sensory attributes and modalities, Proceedings of the Royal Society of London B: Biological Sciences,277(1692):2281-90. Meeting abstract presented at VSS 2012

Listening to White Noise Counteracts Visual and Haptic Pseudoneglect

Neurologically intact individuals usually show a leftward bias in line bisection, a tendency known as "pseudoneglect", likely reflecting a right-hemisphere dominance in controlling the allocation of spatial attention. Studies in brain-damaged patients with left visuospatial neglect have reported that auditory stimulation may reduce the deficit, both in a spatially dependent and in a spatially independent way. Here we show for the first time that the concurrent binaural presentation of auditory white noise affects healthy individuals' performance in both visual and haptic bisection, reducing their leftward error. We suggest that this effect depends on the noise boosting alertness and restoring the hemispheric activation balance. Our data clearly show that task-irrelevant auditory noise crossmodally affects the allocation of spatial resources in both the haptic and the visual space; future research may clarify whether these effects are specific for the type of auditory stimulation.

Temporal Aspects of Sound Induced Visual Fission and Fusion in the Double-Flash Illusion Paradigm

The sound-induced flash illusion (SIFI) is thought to be due to early audiovisual connections which allow rapid interplay between early auditory and visual cortices. However, the temporal relationship between the perception of physically presented and additional illusory flashes has not yet been directly addressed. We presented participants with a stream of four brief auditory white noise bursts separated by gaps of 60ms (SOA=70ms) and one or two brief flashes which could appear in any of the gaps between noise bursts (positions 1–4) or before the auditory stream (position 0). All possible combinations were randomized and presented equally often. First, participants were asked to indicate the perceived number of flashes, and second, to indicate the perceived position of the flash(es). Thus we could compare the physical separation of the flashes with the perceived separation. We report the following results: 1) In illusory-fission trials the average perceived distance between the perceived flashes is ∼100ms. 2) SIFI is strongest when the flash is presented at position 1 and 2. 3) The extent of experienced fission-illusion depends on performance in aligning flashes with auditory gaps. 4) We observed auditory induced de-fusion which is strongest at position 1 and again correlated to overall task performance.

Assessing the audiotactile Colavita effect in near and rear space

The Colavita effect occurs when participants performing a speeded detection/discrimination task preferentially report the visual component of pairs of audiovisual or visuotactile stimuli. To date, however, researchers have failed to demonstrate an analogous effect for audiotactile stimuli (Hecht and Reiner in Exp Brain Res 193:307-314, 2009). Here, we investigate whether an audiotactile Colavita effect can be demonstrated by manipulating either the physical features of the auditory stimuli presented in frontal (Experiment 1) or rear space (Experiment 3), or the relative and absolute position of auditory and tactile stimuli in frontal (Experiment 2) or rear space (Experiment 3). The participants showed no evidence of responding preferentially to one of the sensory components of the bimodal stimuli when they were presented from a single location in frontal space (Experiment 1). However, a significant audiotactile Colavita effect was demonstrated in Experiments 2 and 3, with participants preferentially reporting the auditory (rather than tactile) stimulus on the bimodal target trials. In Experiment 3, an audiotactile Colavita effect was reported for auditory white noise bursts but not for pure tones and selectively for those stimuli presented from the same (rather than from the opposite) side. Taken together, these results therefore suggest that when a tactile and an auditory stimulus are presented from a single frontal location, participants do not preferentially report one of the two sensory components (Experiment 1). In contrast, when the stimuli are presented from different locations, people preferentially report the auditory component, especially when they are spatially coincident (Experiments 2 and 3). Moreover, for stimuli presented from rear space, the Colavita effect was only observed for auditory stimuli consisting of white noise bursts (but not for pure tones), suggesting that this kind of stimuli are more likely to be bound together with somatosensory stimuli in rear space.