Sound Cues Research Articles

Fish behavior recognition based on an audio-visual multimodal interactive fusion network

In light of the challenges imposed by fish behavior recognition, which arise from environmental noise and dim lighting in aquaculture environments and adversely affect the effectiveness of unimodal recognition methods based on either sound or visual cues, this paper proposes a fish behavior recognition model, Mul-SEResNet50, based on the fusion of audio and visual information. To address issues such as image blurring and indistinct sounds in aquaculture environments, which hinder the effectiveness of multimodal fusion and complementary modalities, a multimodal interaction fusion (MIF) module is introduced. This module integrates audio-visual modalities at multiple stages to achieve a more comprehensive joint feature representation. To enhance complementarity during the fusion process, we designed a U-shaped bilinear fusion structure to fully utilize multimodal information, capture cross-modal associations, and extract high-level features. Furthermore, to address the potential loss of key features, a temporal aggregation and pooling (TAP) layer is introduced to preserve more fine-grained features by extracting both the maximum and average values within pooling regions. To validate the effectiveness of the proposed model, both ablation experiments and comparative experiments are conducted. The results demonstrate that Mul-SEResNet50 achieves a 5.04 % accuracy improvement over SEResNet50 without sacrificing detection speed. Compared to the state-of-the-art U-FusionNet-ResNet50 +SENet model, Mul-SEResNet50 achieves accuracy and F1 score improvements of 0.47 % and 1.32 %, respectively. These findings confirm the efficacy of the proposed model in terms of accurately recognizing fish behavior, facilitating the precise monitoring of fish behavior.

Associating sensory cues with incoming seizures: developing an animal model of auras

For patients with epilepsy, one of the biggest problems is the unpredictability of the time when the next seizure will occur. Interestingly, some epileptic patients experience a sensory sensation preceding seizures, called aura, which helps them move to safety before a seizure. Here, we describe the development of the first animal model of auras, which could allow for a more detailed study of this phenomenon. Specifically, in mice, we presented sensory stimuli (sound and light cues) a few seconds before kindling an animal to induce seizures. Animals were kindled by electrical stimulation in the basolateral amygdalar nucleus. Over the course of stimulation sessions, animals started showing progressively stronger freezing behavior to sensory cues preceding kindling. Interestingly, seizures are known to cause retrograde amnesia, thus it was surprising that the association between seizures and preceding sensory cues developed in all experimental animals. In summary, our experiments show that similarly to auras, a sensory sensation can be associated with incoming generalized seizures and is not erased by retrograde amnesia.

NeuroCamTags: Long-Range, Battery-free, Wireless Sensing with Neuromorphic Cameras

In this research, we introduce NeuroCamTags, a battery-free platform designed to detect a range of rich human interactions and activities in entire rooms and floors without the need for batteries. The NeuroCamTag system comprises low-cost tags that harvest ambient light energy and utilize high-frequency modulation of light-emitting diodes (LEDs) for wireless communication. These visual signals are captured by an available neuromorphic camera, which boasts temporal resolution and frame rates an order of magnitude higher than those of conventional cameras. We present an event processing pipeline that allows simultaneous localization and identification of multiple unique tags. NeuroCamTags offer a wide range of functionalities, providing battery-free wireless sensing for various physical stimuli, including changes in temperature, contact, button presses, key presses, and even sound cues. Our empirical evaluations demonstrate impressive accuracy at long ranges up to 200 feet. In addition to these findings, we consider a range of applications such as battery-free input devices, tracking of human movement, and long-range detection of human activities in various environments such as kitchens, workshops, etc. By reducing reliance on batteries, NeuroCamTags promotes eco-friendliness and opens doors to exciting possibilities in smart environment technology.

Different mechanisms of contextual inference govern associatively learned and sensory-evoked postural responses

Human standing balance relies on the continuous monitoring and integration of sensory signals to infer our body's motion and orientation within the environment. However, when sensory information is no longer contextually relevant to balancing the body (e.g., when sensory and motor signals are incongruent), sensory-evoked balance responses are rapidly suppressed, much earlier than any conscious perception of changes in balance control. Here, we used a robotic balance simulator to assess whether associatively learned postural responses are similarly modulated by sensorimotor incongruence and contextual relevance to postural control. Twenty-nine participants in three groups were classically conditioned to generate postural responses to whole-body perturbations when presented with an initially neutral sound cue. During catch and extinction trials, participants received only the auditory stimulus but in different sensorimotor states corresponding to their group: 1) during normal active balance, 2) while immobilized, and 3) throughout periods where the computer subtly removed active control over balance. In the balancing and immobilized states, conditioned responses were either evoked or suppressed, respectively, according to the (in)ability to control movement. Following the immobilized state, conditioned responses were renewed when balance was restored, indicating that conditioning was retained but only expressed when contextually relevant. In contrast, conditioned responses persisted in the computer-controlled state even though there was no causal relationship between motor and sensory signals. These findings suggest that mechanisms responsible for sensory-evoked and conditioned postural responses do not share a single, central contextual inference and assessment of their relevance to postural control, and may instead operate in parallel.

The Rapid Decline in Interaural-Time-Difference Sensitivity for Pure Tones Can Be Explained by Peripheral Filtering.

The interaural time difference (ITD) is a primary horizontal-plane sound localization cue computed in the auditory brainstem. ITDs are accessible in the temporal fine structure of pure tones with a frequency of no higher than about 1400Hz. How listeners' ITD sensitivity transitions from very best sensitivity near 700Hz to impossible to detect within 1 octave currently lacks a fully compelling physiological explanation. Here, it was hypothesized that the rapid decline in ITD sensitivity is dictated not by a central neural limitation but by initial peripheral sound encoding, specifically, the low-frequency (apical) portion of the cochlear excitation pattern produced by a pure tone. ITD sensitivity was measured in 16 normal-hearing listeners as a joint function of frequency (900-1500Hz) and level (10-50dB sensation level). Performance decreased with increasing frequency and decreasing sound level. The slope of performance decline was 90dB/octave, consistent with the low-frequency slope of the cochlear excitation pattern. Fine-structure ITD sensitivity near 1400Hz may be conveyed primarily by "off-frequency" activation of neurons tuned to lower frequencies near 700Hz. Physiologically, this could be realized by having neurons sensitive to fine-structure ITD up to only about 700Hz. A more extreme model would have only a single narrow channel near 700Hz that conveys fine-structure ITDs. Such a model is a major simplification and departure from the classic formulation of the binaural display, which consists of a matrix of neurons tuned to a wide range of relevant frequencies and ITDs.

Awake targeted memory reactivation doesn't work.

Memories are pliable and can be biased by post-encoding information. In targeted memory reactivation (TMR) studies, participants encode information then sleep, during which time sounds or scents that were previously associated with the encoded images are re-presented in an effort to trigger reactivation of the associated memory traces. Upon subsequent testing, memory for reactivated items is often enhanced. Is sleep essential for this process? The literature on awake TMR is small and findings are mixed. Here, we asked English-speaking adults to learn Japanese vocabularywords. During a subsequent active rest phase, participants played Tetris while sound cues associated with the vocabulary words were presented. Results showed that when memories were reactivated, they were either disrupted (Experiment 1) or unaffected (Experiments 2, 3). These findings indicate that awake TMR is not beneficial, and may actually impair subsequent memory. These findings have important implications for research on memory consolidation and reactivation.

The addition of a spatial auditory cue improves spatial updating in a virtual reality navigation task.

Auditory cues are integrated with vision and body-based self-motion cues for motion perception, balance, and gait, though limited research has evaluated their effectiveness for navigation. Here, we tested whether an auditory cue co-localized with a visual target could improve spatial updating in a virtual reality homing task. Participants navigated a triangular homing task with and without an easily localizable spatial audio signal co-located with the home location. The main outcome was unsigned angular error, defined as the absolute value of the difference between the participant's turning response and the correct response towards the home location. Angular error was significantly reduced in the presence of spatial sound compared to a head-fixed identical auditory signal. Participants' angular error was 22.79° in the presence of spatial audio and 30.09° in its absence. Those with the worst performance in the absence of spatial sound demonstrated the greatest improvement with the added sound cue. These results suggest that auditory cues may benefit navigation, particularly for those who demonstrated the highest level of spatial updating error in the absence of spatial sound.

Comparing targeted memory reactivationduring slow wave sleep and sleep stage 2.

Sleep facilitates declarative memory consolidation, which is assumed to rely on the reactivation of newly encoded memories orchestrated by the temporal interplay of slow oscillations (SO), fast spindles and ripples. SO as well as the number of spindles coupled to SO are more frequent during slow wave sleep (SWS) compared to lighter sleep stage 2 (S2). But, it is unclear whether memory reactivation is more effective during SWS than during S2. To test this question, we applied Targeted Memory Reactivation (TMR) in a declarative memory design by presenting learning-associated sound cues during SWS vs. S2 in a counterbalanced within-subject design. Contrary to our hypothesis, memory performance was not significantly better when cues were presented during SWS. Event-related potential (ERP) amplitudes were significantly higher for cues presented during SWS than S2, and the density of SO and SO-spindle complexes was generally higher during SWS than during S2. Whereas SO density increased during and after the TMR period, SO-spindle complexes decreased. None of the parameters were associated with memory performance. These findings suggest that the efficacy of TMR does not depend on whether it is administered during SWS or S2, despite differential processing of memory cues in these sleep stages.

The effectiveness of a virtual fencing technology to allocate pasture and herd cows to the milking shed

Virtual fencing technology provides an opportunity to rethink the management of intensive grazing systems in general, yet most studies have used products developed and applied to more extensive livestock systems. This research aimed to assess the application of a virtual fencing technology developed for the intensive pastoral dairy industry. The Halter system uses 2 primary cues, sound and vibration, and one aversive secondary cue, a low energy electrical pulse, to confine cows to a pasture allocation and remotely herd cows. Two groups of 40 mid-lactation multiparous dairy cows were studied (Bos taurus, predominantly Friesian and Friesian × Jersey, parity 1-8). Cows were milked twice per day and provided 9 kg pasture DM/day in a 24-h allocation, supplemented with 7 kg silage and 6 kg grain DM/day. Training to the Halter system occurred over 10 d after which cows were managed with the technology for a further 28 d. The type and time of cues delivered was recorded by each collar and communicated via a base-station to cloud data storage. Cows took less than a day to start responding to the sound cues delivered while held on a pasture allocation and were moving to the milking parlor without human intervention by d 4 of training. On training d 1, at least 60% of sound cues resulted in an electrical pulse. Across training d 2-10, 6.4% of sound cues resulted in a pulse. After the 10-d training period, 2.6% of sound cues resulted in a pulse. During the management period, 90% of cows spent ≤1.7 min/d beyond the virtual fence, received ≤ 0.71 pulse/d in the paddock and received ≤ 1 pulse/d during virtual herding to the parlor. By the final week of the management period, 50% of cows received zero pulses/week in the paddock and 35% received zero pulses/week during virtual herding. The number of pulses delivered per day and the pulse:sound cue ratio was lower in this study than that previously reported using other virtual fencing technologies. We conclude that the Halter technology is successful at containing lactating dairy cows in an intensive grazing system as well as at remotely herding animals to the milking parlor.

Neurophysiological analysis of disadvantageous social inequity: Exploring emotional behavior changes and c-Fos expression in a male rat model

Humans and other animals exhibit aversive behavioral and emotional responses to unequal reward distributions compared with their conspecifics. Despite the significance of this phenomenon, experimental animal models designed to investigate social inequity aversion and delve into the underlying neurophysiological mechanisms are limited. In this study, we developed a rat model to determine the effects of socially equal or unequal reward and stress on emotional changes in male rats. During the training session, the rats were trained to escape when a sound cue was presented, and they were assigned to one of the following groups: all escaping rats [advantageous equity (AE)], freely moving rats alongside a restrained rat [advantageous inequity (AI)], all restrained rats [disadvantageous equity (DE)], and a rat restrained in the presence of freely moving companions [disadvantageous inequity (DI)]. During the test session, rats in the advantageous group (AE and AI) escaped after the cue sound (expected reward acquisition), whereas rats in the disadvantageous group (DE and DI) could not escape despite the cue being presented (expected reward deprivation). Emotional alteration induced by exposure to restraint stress under various social interaction circumstances was examined using an open field test. Notably, the DI group displayed reduced exploration of the center zone during the open field tests compared with the other groups, indicating heightened anxiety-like behaviors in response to reward inequity. Immunohistochemical analysis revealed increased c-Fos expression in the medial prefrontal and orbitofrontal cortices, coupled with reduced c-Fos expression in the striatum and nucleus accumbens under DI conditions, in contrast to the other experimental conditions. These findings provide compelling evidence that rats are particularly sensitive to reward inequity, shedding light on the neurophysiological basis for distinct cognitive processes that manifest when individuals are exposed to social equity and inequity situations.

Population coding of time-varying sounds in the nonlemniscal inferior colliculus.

The inferior colliculus (IC) of the midbrain is important for complex sound processing, such as discriminating conspecific vocalizations and human speech. The IC's nonlemniscal, dorsal "shell" region is likely important for this process, as neurons in these layers project to higher-order thalamic nuclei that subsequently funnel acoustic signals to the amygdala and nonprimary auditory cortices, forebrain circuits important for vocalization coding in a variety of mammals, including humans. However, the extent to which shell IC neurons transmit acoustic features necessary to discern vocalizations is less clear, owing to the technical difficulty of recording from neurons in the IC's superficial layers via traditional approaches. Here, we use two-photon Ca2+ imaging in mice of either sex to test how shell IC neuron populations encode the rate and depth of amplitude modulation, important sound cues for speech perception. Most shell IC neurons were broadly tuned, with a low neurometric discrimination of amplitude modulation rate; only a subset was highly selective to specific modulation rates. Nevertheless, neural network classifier trained on fluorescence data from shell IC neuron populations accurately classified amplitude modulation rate, and decoding accuracy was only marginally reduced when highly tuned neurons were omitted from training data. Rather, classifier accuracy increased monotonically with the modulation depth of the training data, such that classifiers trained on full-depth modulated sounds had median decoding errors of ∼0.2 octaves. Thus, shell IC neurons may transmit time-varying signals via a population code, with perhaps limited reliance on the discriminative capacity of any individual neuron.NEW & NOTEWORTHY The IC's shell layers originate a "nonlemniscal" pathway important for perceiving vocalization sounds. However, prior studies suggest that individual shell IC neurons are broadly tuned and have high response thresholds, implying a limited reliability of efferent signals. Using Ca2+ imaging, we show that amplitude modulation is accurately represented in the population activity of shell IC neurons. Thus, downstream targets can read out sounds' temporal envelopes from distributed rate codes transmitted by populations of broadly tuned neurons.

Utricular Dysfunction and Hearing Impairment Affect Spatial Navigation in Community-Dwelling Healthy Adults: Analysis from the Baltimore Longitudinal Study of Aging

Plain Language SummarySpatial navigation, the ability to move through one’s environment, is a complex skill utilized in everyday life. The effects of specific balance and hearing deficits on spatial navigation have not been extensively studied. Thus, we analyzed data from 182 participants in the Baltimore Longitudinal Study of Aging who completed balance, hearing, and spatial navigation tests to determine if hearing impairment may adversely affect spatial navigation and if combined deficits in balance and hearing further impair navigation ability. Our analyses accounted for the confounding effects of age, sex, and cognition on aspects of spatial navigation performance. We found that deficits in hearing and in the balance organ that senses horizontal translational movements were associated with worse performance on spatial navigation. However, deficits in the balance organs that sense vertical translational movements and horizontal rotational movements were not associated with worse spatial navigation ability. Surprisingly, we found that those with combined balance and hearing deficits did not perform significantly worse on spatial navigation than those with deficits in either balance or hearing alone. We believe that the abnormal function of the horizontal translational movement sensors likely explains the gait disorientation experienced by persons with inner ear problems. Additionally, we propose that hearing deficits impede one’s ability to use real-time sound cues to guide navigation. Many of our participants had mild deficits; thus, further research on the effects of more severe balance and hearing deficits on spatial navigation is needed to gain a better understanding of how different sensory inputs contribute to spatial navigation ability.

Streamlined Workforce Management System Using AI

In today's digital landscape, face recognition technology has emerged as a versatile and non-invasive tool used across sectors, despite its lower accuracy compared to iris or fingerprint recognition. Its applications range from security and authentication to optimizing attendance systems in educational institutions and workplaces. This paper introduces an innovative class attendance system employing face recognition technology, replacing manual processes prone to inaccuracies like proxy attendance. The system involves database creation from student images, utilizing Haar-Cascade classifiers for face detection, and Local Binary Pattern Histogram algorithms for live recognition from classroom video streams. It automates attendance data distribution to faculty members, enhancing efficiency and precision. Simultaneously, the security industry necessitates alert and vigilant security personnel to prevent breaches. A sophisticated hybrid system, leveraging machine learning techniques like OpenCV and EAR/MAR algorithms alongside UHD cameras, detects guard drowsiness and alerts them promptly using sound cues and preventive measures, ensuring continual vigilance. This innovative hybrid system fortifies security guard surveillance, mitigating potential vulnerabilities due to lapses in attentiveness. Key Word: Face Recognition Technology, Biometrics, Attendance Management, Security, Authentication, Surveillance, Machine Learning, Open CV, Security Guard Monitoring, Vigilance, Drowsiness Detection.

Unidentified fish sounds as indicators of coral reef health and comparison to other acoustic methods

As biodiversity hotspots, coral reefs are rich with sound cues. Monitoring these soundscapes for changes is essential as coral reefs decline around the world rapidly. Despite this, acoustic metrics that reliably represent reef health are still debated, and ground-truthing of methods are limited. We sought to investigate the occurrence and prevalence of fish sounds in relation to reef health, providing a foundation to compare assessment methods. We first quantified fish call rates for three U.S. Virgin Islands reefs exhibiting different community assemblages, by manually annotating fish calls across 8 days per site. Call rates were then compared with traditional visual surveys, and several acoustic methods commonly used in underwater soundscape research. Manually detected fish call rates successfully differentiated between the three reefs, capturing variation in crepuscular activity levels and predicting hard coral cover, fish abundance, and fish species richness. Meanwhile, most acoustic indices failed to parse out fine distinctions among the three sites, although sound pressure level showed the greatest correlation to call rates. Development of methods to improve the utilization of unknown fish sounds, such as automatic detection and classification tools, supports global sound library efforts and is essential to implement large-scale passive acoustic monitoring of coral reefs.

Particle motion polarization of offshore fish vocalizations, boat noise, and ambient soundscapes

Acoustic particle motion is an important acoustic cue for fish and aquatic invertebrate hearing. When reported for bioacoustics applications, it is often described as a magnitude only. However, particle motion is a vector quantity with polarization information (including directionality) relevant to detection and localization of sound cues by fishes and invertebrates. This study applied established metrics of particle motion polarization including ellipse amplitude, angle, orientation, and degree of polarization, to compare sounds of fish vocalizations with that of boat and ambient sounds at a 900 m-deep site (in the Atlantic Deepwater Ecosystem Observatory Network) offshore of Florida. Polarization metrics were computed for bivariate signals in the plane formed by the horizontal source-receiver and vertical axes. Boat sound polarization was quantified at multiple distances from the closest point of approach. Fish and boat sounds had narrower particle motion ellipses and larger amplitudes in the horizontal compared to ambient sounds that were more circular with larger relative vertical amplitudes. Fish and boat sounds were often strongly polarized, which may allow spatial release from masking given sufficient angular separation of sounds. This analysis framework has promising applications for monitoring in situ directionality of fish and other animal vocalizations and for modelling directional masking.

Avoidance, confusion or solitude? Modelling how noise pollution affects whale migration

Many baleen whales are renowned for their acoustic communication. Under pristine conditions, this communication can plausibly occur across hundreds of kilometres. Frequent vocalisations may allow a dispersed migrating group to maintain contact, and therefore benefit from improved navigation via the “wisdom of the crowd”. Human activities have considerably inflated ocean noise levels. Here we develop a data-driven mathematical model to investigate how ambient noise levels may inhibit whale migration. Mathematical models allow us to simultaneously simulate collective whale migration behaviour, auditory cue detection, and noise propagation. Rising ambient noise levels are hypothesised to influence navigation through three mechanisms: (i) diminished communication space; (ii) reduced ability to hear external sound cues and; (iii) triggering noise avoidance behaviour. Comparing pristine and current soundscapes, we observe navigation impairment that ranges from mild (increased journey time) to extreme (failed navigation). Notably, the three mechanisms induce qualitatively different impacts on migration behaviour. We demonstrate the model’s potential predictive power, exploring the extent to which migration may be altered under future shipping and construction scenarios.

Advancing Auscultation Education: Signals Visualization as a Novel Tool for Enhancing Pathological Respiratory Sounds Detection

Abstract Introduction: Auscultation remains a pivotal diagnostic modality for various respiratory pathologies. To augment its clinical relevance, the continuous expansion of our understanding of pulmonary acoustics, coupled with the advancement of auscultation recording and analysis methodologies, is imperative. Material and methods: We investigated how the bimodal presentation of auscultatory signals (sound and visual cue perception) influences the subjective efficacy of pathological respiratory sound detection, which is a critical step in the development of a new auscultation tool. Recordings of pediatric breath sounds were presented in three different forms - audio only, visual representation only (spectrogram) or audiovisual (both together). The F1-score, sensitivity and specificity parameters were calculated and compared to the gold standard (GS). Subsequent to the detection experiment, participants completed a survey to subjectively assess the usability of spectrograms in the procedure. Results: Over 60% of all responders ranked the spectrogram as important (40.8%) or very important (21.1%). Moreover, 11.3% of all participants found this new form of presentation of auscultation results to be more useful than the evaluation of sound only. The addition of visual information did not statistically significantly change the evaluation of the sounds themselves, an observable trend implies that enhancing audio recordings with visualizations can enhance detection performance. This is evident in the 4 p.p. and 2 p.p. sensitivity increments for physicians and students, respectively, even without specialized visual training. Conclusions: Our research findings indicate that the integration of spectrograms with conventional auditory assessment, albeit based on observed trends and survey responses, presents a promising avenue for improving the precision and quality of medical education, as well as enhancing diagnosis and monitoring processes.

Pedestrian auditory perception of approaching vehicles from behind in shared space: the impact of quietness of electric vehicles

The reduced auditory detectability of electric vehicles (EVs) at low speeds has elicited concerns for pedestrian safety. In shared space where traffic regulations and physical separations are absent, the auditory perception of approaching vehicles from behind is a critical factor in preventing pedestrian-vehicle collisions, for both sighted and (blind) visually impaired people. This study explored the effects of the sound pressure level of background noise, vehicle type, vehicle manoeuvre and approaching direction on auditory perception. Vehicle sounds were recorded in a car park under controlled driving behaviour, and the background noise was recorded in a typical shared space. These sounds were then synthesized and reproduced in an anechoic chamber. 9 participants were presented with 48 sound cues. Their auditory perception was assessed by detection rate, direction determination, and detection distance of approaching vehicles. Results indicate that only 6% sound cues were missed by participants and it happened mostly at the highest background noise level (69 dBA), and all reported instances of approaching direction were accurately identified by the participants. All aforementioned factors were found to have a significant impact on detection distance. A regression model was also conducted and shows relative high prediction power for the detection distance (adjusted R2=0.703). The comparison between stopping distance and detection distance showed that in many experimental conditions, approaching conventional vehicles could be detected away from the stopping distance while electric vehicles could not. This paper proposes a conceptual framework for understanding the role of auditory perception in EV-pedestrian interactions, and the pilot lab experiment suggests that the quietness of EV may cause safety issue for pedestrians in shared space.

Rearing and Shipping of Uranotaenia lowii, a Frog-Biting Mosquito.

Many studies on mosquito biology rely on laboratory-reared colonies, emphasizing the need for standardized protocols to investigate critical aspects such as disease biology, mosquito behavior, and vector control methods. While much knowledge is derived from anthropophilic species from genera like Anopheles, Aedes, and Culex, there is a growing interest in studying mosquitoes that feed on non-human hosts. This interest stems from the desire to gain a deeper understanding of the evolution of diverse host range use and host specificity. However, there is currently a limited number of comprehensive protocols for studying such species. Considering this gap, we present a protocol for rearing Uranotaenia lowii, a mosquito species specialized in feeding on anuran amphibians by eavesdropping on host-emitted sound cues. Additionally, we provide instructions for successfully shipping live specimens to promote research on this species and similar ones. This protocol helps fill the current gap in comprehensive guidelines for rearing and maintaining colonies of anuran host-biting mosquitoes. It serves as a valuable resource for researchers seeking to establish colonies of mosquito species from the Uranotaeniini tribe. Ultimately, this protocol may facilitate research on the evolutionary ecology of Culicidae, as this family has recently been proposed to have originated from a frog-feeding ancestor. Key features • Rearing and maintenance of colonies of non-human host-biting mosquitoes that feed on frogs using host-emitted acoustic cues. • Provides shipping guidelines aimed to enhance the establishment of colonies by new research groups and specimen exchanges between labs.

Large-scale single-neuron speech sound encoding across the depth of human cortex

Understanding the neural basis of speech perception requires that we study the human brain both at the scale of the fundamental computational unit of neurons and in their organization across the depth of cortex. Here we used high-density Neuropixels arrays1–3 to record from 685 neurons across cortical layers at nine sites in a high-level auditory region that is critical for speech, the superior temporal gyrus4,5, while participants listened to spoken sentences. Single neurons encoded a wide range of speech sound cues, including features of consonants and vowels, relative vocal pitch, onsets, amplitude envelope and sequence statistics. Neurons at each cross-laminar recording exhibited dominant tuning to a primary speech feature while also containing a substantial proportion of neurons that encoded other features contributing to heterogeneous selectivity. Spatially, neurons at similar cortical depths tended to encode similar speech features. Activity across all cortical layers was predictive of high-frequency field potentials (electrocorticography), providing a neuronal origin for macroelectrode recordings from the cortical surface. Together, these results establish single-neuron tuning across the cortical laminae as an important dimension of speech encoding in human superior temporal gyrus.