Abstract: We hear the melody in music, but we feel the beat. We demonstrate that the perception of musical rhythm is a multisensory experience in infancy. In particular, movement of the body, by bouncing on every second versus every third beat of an ambiguous auditory rhythm pattern, influences whether that auditory rhythm pattern is encoded in duple form (a march) or in triple form (a waltz). Visual information is not necessary for the effect, indicating that it likely reflects a strong, early-developing interaction between auditory and vestibular information in the human nervous system.

Abstract: This review presents an overview of a challenging problem in auditory perception, the cocktail party phenomenon, the delineation of which goes back to a classic paper by Cherry in 1953. In this review, we address the following issues: (1) human auditory scene analysis, which is a general process carried out by the auditory system of a human listener; (2) insight into auditory perception, which is derived from Marr's vision theory; (3) computational auditory scene analysis, which focuses on specific approaches aimed at solving the machine cocktail party problem; (4) active audition, the proposal for which is motivated by analogy with active vision, and (5) discussion of brain theory and independent component analysis, on the one hand, and correlative neural firing, on the other.

Abstract: Speech recognition in noise and music perception is especially challenging for current cochlear implant users. The present study utilizes the residual acoustic hearing in the nonimplanted ear in five cochlear implant users to elucidate the role of temporal fine structure at low frequencies in auditory perception and to test the hypothesis that combined acoustic and electric hearing produces better performance than either mode alone. The first experiment measured speech recognition in the presence of competing noise. It was found that, although the residual low-frequency (<1000 Hz) acoustic hearing produced essentially no recognition for speech recognition in noise, it significantly enhanced performance when combined with the electric hearing. The second experiment measured melody recognition in the same group of subjects and found that, contrary to the speech recognition result, the low-frequency acoustic hearing produced significantly better performance than the electric hearing. It is hypothesized that listeners with combined acoustic and electric hearing might use the correlation between the salient pitch in low-frequency acoustic hearing and the weak pitch in the envelope to enhance segregation between signal and noise. The present study suggests the importance and urgency of accurately encoding the fine-structure cue in cochlear implants.

Abstract: Audiovisual perception and imitation are essential for musical learning and skill acquisition. We compared professional pianists to musically naive controls with fMRI while observing piano playing finger–hand movements and serial finger–thumb opposition movements both with and without synchronous piano sound. Pianists showed stronger activations within a fronto-parieto-temporal network while observing piano playing compared to controls and contrasted to perception of serial finger–thumb opposition movements. Observation of silent piano playing additionally recruited auditory areas in pianists. Perception of piano sounds coupled with serial finger–thumb opposition movements evoked increased activation within the sensorimotor network. This indicates specialization of multimodal auditory–sensorimotor systems within a fronto-parieto-temporal network by professional musical training. Musical ''language,'' which is acquired by observation and imitation, seems to be tightly coupled to this network in accord with an observation–execution system linking visual and auditory perception to motor performance.

Abstract: Perceptual consequences of disrupted auditory nerve activity were systematically studied in 21 subjects who had been clinically diagnosed with auditory neuropathy (AN), a recently defined disorder characterized by normal outer hair cell function but disrupted auditory nerve function. Neurological and electrophysical evidence suggests that disrupted auditory nerve activity is due to desynchronized or reduced neural activity or both. Psychophysical measures showed that the disrupted neural activity has minimal effects on intensity-related perception, such as loudness discrimination, pitch discrimination at high frequencies, and sound localization using interaural level differences. In contrast, the disrupted neural activity significantly impairs timing related perception, such as pitch discrimination at low frequencies, temporal integration, gap detection, temporal modulation detection, backward and forward masking, signal detection in noise, binaural beats, and sound localization using interaural time differences. These perceptual consequences are the opposite of what is typically observed in cochlear-impaired subjects who have impaired intensity perception but relatively normal temporal processing after taking their impaired intensity perception into account. These differences in perceptual consequences between auditory neuropathy and cochlear damage suggest the use of different neural codes in auditory perception: a suboptimal spike count code for intensity processing, a synchronized spike code for temporal processing, and a duplex code for frequency processing. We also proposed two underlying physiological models based on desynchronized and reduced discharge in the auditory nerve to successfully account for the observed neurological and behavioral data. These methods and measures cannot differentiate between these two AN models, but future studies using electric stimulation of the auditory nerve via a cochlear implant might. These results not only show the unique contribution of neural synchrony to sensory perception but also provide guidance for translational research in terms of better diagnosis and management of human communication disorders.

Abstract: Attending to a stimulus is known to enhance the neural responses to that stimulus. Recent experiments on visual attention have shown that this modulation can have object-based characteristics, such that, when certain parts of a visual object are attended, other parts automatically also receive enhanced processing. Here, we investigated whether visual attention can modulate neural responses to other components of a multisensory object defined by synchronous, but spatially disparate, auditory and visual stimuli. The audiovisual integration of such multisensory stimuli typically leads to mislocalization of the sound toward the visual stimulus (ventriloquism illusion). Using event-related potentials and functional MRI, we found that the brain's response to task-irrelevant sounds occurring synchronously with a visual stimulus from a different location was larger when that accompanying visual stimulus was attended versus unattended. The event-related potential effect consisted of sustained, frontally distributed, brain activity that emerged relatively late in processing, an effect resembling attention-related enhancements seen at earlier latencies during intramodal auditory attention. Moreover, the functional MRI data confirmed that the effect included specific enhancement of activity in auditory cortex. These findings indicate that attention to one sensory modality can spread to encompass simultaneous signals from another modality, even when they are task-irrelevant and from a different location. This cross-modal attentional spread appears to reflect an object-based, late selection process wherein spatially discrepant auditory stimulation is grouped with synchronous attended visual input into a multisensory object, resulting in the auditory information being pulled into the attentional spotlight and bestowed with enhanced processing.

Abstract: The relative spatiotemporal correspondence between sensory events affects multisensory integration across a variety of species; integration is maximal when stimuli in different sensory modalities are presented from approximately the same position at about the same time. In the present study, we investigated the influence of spatial and temporal factors on audio-visual simultaneity perception in humans. Participants made unspeeded simultaneous versus successive discrimination responses to pairs of auditory and visual stimuli presented at varying stimulus onset asynchronies from either the same or different spatial positions using either the method of constant stimuli (Experiments 1 and 2) or psychophysical staircases (Experiment 3). The participants in all three experiments were more likely to report the stimuli as being simultaneous when they originated from the same spatial position than when they came from different positions, demonstrating that the apparent perception of multisensory simultaneity is dependent on the relative spatial position from which stimuli are presented.

Abstract: The auditory brain stem response to speech mimics the acoustic characteristics of the speech signal with remarkable fidelity. This makes it possible to derive from it considerable theoretical and clinically applicable information relevant to auditory processing of complex stimuli. Years of research have led to the current characterization of these neural events with respect to the underlying acoustic information they reflect. The majority of data reviewed here originates from studies using a /da/ syllable to elicit the brain stem response, which consists of transient and periodic (frequency following) neural activity. We describe how the human auditory brain stem response separately encodes source and filter characteristics of the acoustic signal, which reflects paralinguistic and linguistic information simultaneously conveyed in speech. In normal-hearing individuals, these two classes of response components (source and filter) are highly correlated within a class but not between classes. This response dissociation becomes pronounced when stimuli are presented in background noise or with faster stimulus rates. In addition, some learning-impaired children show a selective deficiency in the neural encoding of acoustic features associated with the filter characteristics of speech. These children show no deficits in the encoding of source components, further supporting the notion of separate neural mechanisms. Overall, the auditory brain stem response to speech provides a way to access subcortical auditory processing mechanisms and may be used as a biological marker of deficient sound encoding associated with learning and auditory processing disorders.

Abstract: Auditory experience leads to myriad changes in processing in the central auditory system. We recently described task-related plasticity characterized by rapid modulation of spectro-temporal receptive fields (STRFs) in ferret primary auditory cortex (A1) during tone detection. We conjectured that each acoustic task may have its own "signature" STRF changes, dependent on the salient cues that the animal must attend to perform the task. To discover whether other acoustic tasks could elicit changes in STRF shape, we recorded from A1 in ferrets also trained on a frequency discrimination task. Overall, we found a distinct pattern of STRF change, characterized by an expected selective enhancement at target tone frequency but also by an equally selective depression at reference tone frequency. When single-tone detection and frequency discrimination tasks were performed sequentially, neurons responded differentially to identical tones, reflecting distinct predictive values of stimuli in the two behavioral contexts. All results were observed in multiunit as well as single-unit recordings. Our findings provide additional evidence for the presence of adaptive neuronal responses in A1 that can swiftly change to reflect both sensory content and the changing behavioral meaning of incoming acoustic stimuli.

Abstract: When the senses deliver conflicting information, vision dominates spatial processing, and audition dominates temporal processing. We asked whether this sensory specialization results in cross-modal encoding of unisensory input into the task-appropriate modality. Specifically, we investigated whether visually portrayed temporal structure receives automatic, obligatory encoding in the auditory domain. In three experiments, observers judged whether the changes in two successive visual sequences followed the same or different rhythms. We assessed temporal representations by measuring the extent to which both task-irrelevant auditory information and task-irrelevant visual information interfered with rhythm discrimination. Incongruent auditory information significantly disrupted task performance, particularly when presented during encoding; by contrast, varying the nature of the rhythm-depicting visual changes had minimal impact on performance. Evidently, the perceptual system automatically and obligatorily abstracts temporal structure from its visual form and represents this structure using an auditory code, resulting in the experience of "hearing visual rhythms."

Abstract: This study was designed to assess the potential benefits of using spatial auditory warning signals in a simulated driving task. In particular, the authors assessed the possible facilitation of responses (braking or accelerating) to potential emergency driving situations (the rapid approach of a car from the front or from behind) seen through the windshield or the rearview mirror. Across 5 experiments, the authors assessed the efficacy of nonspatial–nonpredictive (neutral), spatially nonpredictive (50% valid), and spatially predictive (80% valid) car horn sounds, as well as symbolic predictive and spatially presented symbolic predictive verbal cues (the words “front” or “back”) in directing the participant’s visual attention to the relevant direction. The results suggest that spatially predictive semantically meaningful auditory warning signals may provide a particularly effective means of capturing attention.

Abstract: Seniors often have more difficulty understanding speech than younger adults, particularly in noisy environments. While loss in peripheral hearing sensitivity explains many of the listening problems of elderly persons, age-related declines in general cognitive skill and central auditory processing also appear to contribute. In this article, we focus primarily on the effects of age on central auditory mechanisms. To this end, we review research examining a central locus for deficits in temporal processing and summarize behavioral and event-related potential findings from our laboratory's research on the effects of aging on dichotic listening performance. Results show that age-related deficits in interhemispheric information processing may underlie some of the listening problems among seniors. We also discuss implications for clinical audiological rehabilitative efforts in this population.

Abstract: The present study investigated 3-year-old children's perception and production of Mandarin lexical tones in monosyllabic words. Thirteen 3-year-old, Mandarin-speaking children participated in the study. Tone perception was examined by a picture-pointing task, and tone production was investigated by picture naming. To compare children's productions with the adult forms, 4 mothers of the children were asked to say the same set of words to their children in a picture-reading activity. The children's and mothers' productions were low-pass filtered at 500 Hz and 400 Hz, respectively, to eliminate segmental information. Ten Mandarin-speaking judges identified the productions of tones from the filtered speech. Adult productions were more accurately identified than productions of the children. The children perceived the level, rising, and falling tones with relatively high accuracy. The dipping tone posed the greatest difficulty for the children in both perception and production.

Abstract: Monkeys trained preoperatively on a task designed to assess auditory recognition memory were impaired after removal of either the rostral superior temporal gyrus or the medial temporal lobe but were unaffected by lesions of the rhinal cortex. Behavioral analysis indicated that this result occurred because the monkeys did not or could not use long-term auditory recognition, and so depended instead on short-term working memory, which is unaffected by rhinal lesions. The findings suggest that monkeys may be unable to place representations of auditory stimuli into a long-term store and thus question whether the monkey's cerebral memory mechanisms in audition are intrinsically different from those in other sensory modalities. Furthermore, it raises the possibility that language is unique to humans not only because it depends on speech but also because it requires long-term auditory memory.

Abstract: Background: Williams syndrome (WS), a neurodevelopmental disorder, is characterized by pervasive cognitive deficits alongside a relative sparing of auditory perception and cognition. A frequent characteristic of the phenotype is adverse reactions to, and/or fascination with, certain sounds. Previously published reports indicate that people with WS experience hyperacusis, yet careful examination reveals that the term ‘hyperacusis’ has been used indiscriminately in the literature to describe quite different auditory abnormalities. Method: In an effort to clarify and document the incidence of auditory abnormalities in and among people with WS we collected data from parents of people with WS (n ¼ 118) and comparison groups of people with Down syndrome, autism, and normal controls. Results: Our findings revealed four phenomenologically separate auditory abnormalities, all of which were significantly more prevalent in WS than the three comparison groups. Among people with WS, we found relatively few reports of true hyperacusis (lowered threshold for soft sounds) or auditory fascinations/ fixations, whereas 80% reported fearfulness to idiosyncratically particular sounds, and 91% reported lowered uncomfortable loudness levels, or ‘odynacusis.’ Conclusions: Our results confirm anecdotal reports of an unusual auditory phenotype in WS, and provide an important foundation for understanding the nature of auditory experience and pathology in WS. We conclude by reviewing the ways in which the present findings extend and complement recent neuroanatomical and neurophysiological findings on auditory function in people with WS. Keywords: Hyperacusis, oxyacusis, allodynia, Williams syndrome, Williams‐Beuren syndrome, loudness thresholds, odynacusis.

Abstract: Cochlear signal processing.- Nonlinearities at the apex of the cochlea: Implications for auditory perception.- Reconstructing the traveling wave from auditory nerve responses.- A computational algorithm for computing cochlear frequency selectivity: Further studies.- Comparison of the compressive-gammachirp and double-roex auditory filters.- Reaction-time data support the existence of Softness Imperception in cochlear hearing loss.- Normal and impaired level encoding: Effects of noise-induced hearing loss on auditory-nerve responses.- Estimates of Cochlear Compression from Measurements of Loudness Growth.- Additivity of masking and auditory compression.- Psychophysical response growth under suppression.- Brainstem signal processing.- The function(s) of the medial olivocochlear efferent system in hearing.- A computational model of cochlear nucleus neurons.- Study on improving regularity of neural phase locking in single neurons of AVCN via a computational model.- Fibers in the trapezoid body show enhanced synchronization to broadband noise when compared to auditory nerve fibers.- Pitch.- Representations of the pitch of complex tones in the auditory nerve.- Coding of pitch and amplitude modulation in the auditory brainstem: One common mechanism?.- Pitch perception of complex tones within and across ears and frequency regions.- Internal noise and memory for pitch.- Time constants in temporal pitch extraction: A comparison of psychophysical and neuromagnetic data.- Auditory processing at the lower limit of pitch studied by magnetoencephalography.- Frequency modulation.- Auditory maps in the midbrain: The inferior colliculus.- Representation of frequency modulation in the primary auditory cortex of New World monkeys.- Frequency change velocity and acceleration detector: A bird or a red herring?.- Representations of the pitch of complex tones in the auditory nerve.- Streaming.- The role of spectral change detectors in sequential grouping of tones.- Performance measures of auditory organization.- Auditory streaming without spectral cues in hearing-impaired subjects.- Amplitude modulation.- The role of temporal structure in envelope processing.- Detecting changes in amplitude-modulation frequency: A test of the concept of excitation pattern in the temporal-envelope domain.- Modeling the role of duration in intensity increment detection.- Minimum integration times for processing of amplitude modulation.- Responses to complex sounds.- Neural mechanisms for analyzing temporal patterns in echolocating bats.- Time-critical frequency integration of complex communication sounds in the auditory cortex of the mouse.- Transformation of stimulus representations in the ascending auditory system.- AM and FM coherence sensitivity in the auditory cortex as a potential neural mechanism for sound segregation.- Speech.- Auditory perception with slowly-varying amplitude and frequency modulations.- The role of auditory-vocal interaction in hearing.- From sound to meaning: Hierarchical processing in speech comprehension.- Effects of differences in the accent and gender of competing voices on speech segregation.- The Articulation Index is a Shannon channel capacity.- Comodulation masking release.- Comodulation masking release and the role of wideband inhibition in the cochlear nucleus.- The relevance of rate and time cues for CMR in starling auditory forebrain neurons.- Effects of concurrent and sequential streaming in comodulation masking release.- Binaural hearing.- Effects of contralateral sound stimulation on forward masking in the guinea pig.- Inhibition in models of coincidence detection.- What can auditory evoked potentials tell us about binaural processing in humans?.- Sensitivity to changes in interaural time difference and interaural correlation in the inferior colliculus.- Processing of interaural temporal disparities with both "transposed" and conventional stimuli.- Sound localization in the frontal horizontal plane by post-lingually deafened adults fitted with bilateral cochlear implants.- Discrimination of different temporal envelope structures of diotic and dichotic target signals within diotic wide-band noise.- A cat's cocktail party: Psychophysical, neurophysiological, and computational studies of spatial release from masking.- Localization of noise in a reverberant environment.- Listening in real-room reverberation: Effects of extrinsic context.- Psychophysical and physiological studies of the precedence effect and echo threshold in the behaving cat.- Some similarities between the temporal resolution and the temporal integration of interaural time differences.- Binaural "sluggishness" as a function of stimulus bandwidth.- Temporal coding.- Auditory thresholds re-visited.- Discrimination of temporal fine structure by birds and mammals.- Dependence of binaural and cochlear "best delays" on characteristic frequency.- The enigma of cortical responses: Slow yet precise.- Plasticity.- Learning-induced sensory plasticity: Rate code, temporal code, or both?.- Synaptic dynamics and intensity coding in the cochlear nucleus.- Learning and generalization on five basic auditory discrimination tasks as assessed by threshold changes.

Abstract: Evidence suggests that in animals their own species-specific communication sounds are processed predominantly in the left hemisphere. In contrast, processing linguistic aspects of human speech involves the left hemisphere, whereas processing some prosodic aspects of speech as well as other not yet well-defined attributes of human voices predominantly involves the right hemisphere. This leaves open the question of hemispheric processing of universal (species-specific) human vocalizations that are more directly comparable to animal vocalizations. The present functional magnetic resonance imaging study addresses this question. Twenty subjects listened to human laughing and crying presented either in an original or time-reversed version while performing a pitch-shift detection task to control attention. Time-reversed presentation of these sounds is a suitable auditory control because it does not change the overall spectral content. The auditory cortex, amygdala, and insula in the left hemisphere were more strongly activated by original than by time-reversed laughing and crying. Thus, similar to speech, these nonspeech vocalizations involve predominantly left-hemisphere auditory processing. Functional data suggest that this lateralization effect is more likely based on acoustical similarities between speech and laughing or crying than on similarities with respect to communicative functions. Both the original and time-reversed laughing and crying activated more strongly the right insula, which may be compatible with its assumed function in emotional self-awareness.

Abstract: Adult Spanish second language (L2) learners of English and native speakers of English participated in an English perception task designed to investigate their ability to use L2 acoustic-phonetic cu...

Abstract: Sensorimotor integration in the avian song system is crucial for both learning and maintenance of song, a vocal motor behavior. Although a number of song system areas demonstrate both sensory and motor characteristics, their exact roles in auditory and premotor processing are unclear. In particular, it is unknown whether input from the forebrain nucleus interface of the nidopallium (NIf), which exhibits both sensory and premotor activity, is necessary for both auditory and premotor processing in its target, HVC. Here we show that bilateral NIf lesions result in long-term loss of HVC auditory activity but do not impair song production. NIf is thus a major source of auditory input to HVC, but an intact NIf is not necessary for motor output in adult zebra finches.

Abstract: Previous research has suggested that children with specific language impairments (SLI) have deficits in basic speech perception abilities, and this may be an underlying source of their linguistic d...

Abstract: Asperger syndrome (AS) is a developmental disorder of brain function characterized by deficits in social interaction including difficulties in understanding emotional expressions. Children with AS share some of the behavioural characteristics with their parents and AS seems to run particularly in the male members of the same families. The aim of the present study was to determine whether similarities could be found between children with AS and their parents at central auditory processing. It was found that in children with AS the sound encoding, as reflected by the exogenous components of event-related potentials, was similarly abnormal as in both their mothers and fathers. However, their abnormal cortical auditory discrimination, as indexed by the prolonged latency of the mismatch negativity, resembled that of their fathers but not that of their mothers. The present results suggest that complex genetic mechanisms may contribute to auditory abnormalities encountered in children with AS.