The relation between the pip-and-pop effect and audiovisual integration capacity.

Millions of persons worldwide experience varying degrees of hearing loss, traditionally addressed through prosthetic solutions such as hearing aids and cochlear implants. However, a significant proportion of individuals cannot benefit from these technologies, cannot access them, or choose not to use them. In this context, non-prosthetic assistive technologies have emerged as a complementary paradigm, leveraging advances in sensing, artificial intelligence, and wearable computing to transform acoustic information into alternative perceptual representations rather than restoring auditory function. This survey provides a review of such systems, focusing on technologies that enhance environmental awareness, communication, and social interaction. Existing approaches are categorized along two main dimensions: the tasks they perform and the platforms on which they operate. Task-oriented analysis includes sound recognition (speech and non-speech), sound source localization, emotion recognition, sign language recognition, and related emerging functionalities. Platform-based analysis emphasizes wearable devices and mobile solutions enabling real-time and context-aware assistance. The survey further highlights key research trends, including real-time auditory scene analysis, portable processing, and artificial intelligence. It shows that recent studies increasingly demonstrate that combining auditory, visual, and haptic modalities improves robustness and usability in real-world conditions, particularly in noisy and dynamic environments. Finally, open challenges such as energy efficiency, latency, evaluation methodologies, and user acceptance are discussed. By synthesizing existing work and identifying open research directions, this survey aims to provide a structured foundation for future developments in intelligent, non-prosthetic assistive systems that redefine how auditory information is accessed and interpreted.

Information about eye movements is necessary for linking auditory and visual information across space. Recent work has suggested that such signals are incorporated into processing at the level of the ear itself (Gruters, Murphy et al. 2018). Here we report confirmation that the eye movement signals that reach the ear can produce perceptual consequences, via a case report of an unusual participant with tensor tympani myoclonus who hears sounds when she moves her eyes. The sounds she hears could be recorded with a microphone in the ear in which she hears them (left), and occurred for large leftward eye movements to extreme orbital positions of the eyes. The sounds elicited by this participant's eye movements were reminiscent of eye movement-related eardrum oscillations (EMREOs, (Gruters, Murphy et al. 2018, Bröhl and Kayser 2023, King, Lovich et al. 2023, Lovich, King et al. 2023, Lovich, King et al. 2023, Abbasi, King et al. 2025, Sotero Silva, Kayser et al. 2025, King and Groh 2026, Leon, Ramos et al. 2026, Sotero Silva, Brohl et al. 2026)), but were larger and longer lasting than classical EMREOs, helping to explain why they were audible to her. Overall, the observations from this patient help establish that (a) eye movement-related signals specifically reach the tensor tympani muscle and that (b) when there is an abnormality involving that muscle, such signals can lead to actual audible percepts. Given that the tensor tympani contributes to the regulation of sound transmission in the middle ear, these findings support that eye movement signals reaching the ear have functional consequences for auditory perception. The findings also expand the types of medical conditions that produce gaze-evoked tinnitus, to date most commonly observed in connection with acoustic neuromas.

Infants’ ability to integrate auditory and visual information, i.e., audiovisual integration (AVI), emerges during the first year and is crucial for effective communication and early development. However, there is limited longitudinal research on how AVI develops across the first year of life, particularly in infants at elevated likelihood of autism (EL). This study aimed to investigate the developmental trajectories of AVI in response to congruent and incongruent speech stimuli in EL and typical likelihood (TL) infants at 6, 9, and 12 months. Using eye-tracking techniques and the McGurk effect paradigm, we explored infants’ preferential looking behavior towards facial features (eyes vs. mouth) and their response to audiovisual congruence. EL infants were then evaluated at 24 months to explore the associations between AVI and later autism-related traits. Across likelihood groups, infants showed a robust developmental shift from greater attention to the eyes at 6 months toward increased attention to the mouth at 9 and 12 months, consistent with expected developmental changes in audiovisual speech processing. Infants also displayed higher mouth preference in the non-fusible mismatch condition at 6 months, suggesting early sensitivity to audiovisual incongruence. Interestingly, EL infants showed a delayed developmental shift toward mouth-looking across the first year of life. Exploratory outcome analyses revealed that infants showing clinical signs of autism at 24 months displayed a flatter developmental trajectory in eyes-to-mouth preference. The present study emphasizes the importance of examining sensory processing trajectories in EL infants, as delayed shifts in attention to the mouth could signal subtle developmental differences that may have long-term implications for subsequent communication skills.

Flupyradifurone is a butenolide insecticide with growing agricultural significance as a substitute for classical neonicotinoids, which have been partially banned in the EU and other countries. It also acts as an agonist on acetylcholine receptors in the insect central nervous system, but its neurophysiological effects on individual interneurons are poorly understood. Here, we investigated the effects of sublethal flupyradifurone intoxication on the neural processing of auditory information in the field cricket Gryllus bimaculatus. Using a suction electrode on the brain surface, we recorded the spiking activity of the two ascending auditory interneurons AN1 and AN2 while injecting the insecticide into the prothorax. Flupyradifurone caused a dose-dependent decrease in sound-evoked spike responses and an increase in spontaneous spiking activity in both ascending auditory interneurons, eventually leading up to a collapse of all spiking activity the highest dose tested (20µl of 10- 3 mol/l). The substantial increase of spontaneous spiking activity in AN1 and AN2, which started with 20µl of 10- 5 mol/l flupyradifurone treatment, will mask the neuronal coding of relevant acoustic signals required for auditory feature detection in the higher brain circuits. Field crickets rely on AN1 to transmit low-frequency auditory information for pattern recognition in phonotactic mate finding, and on AN2 to transmit high-frequency auditory information for sound source localization in predator avoidance behaviour. The disruption of auditory processing at the level of ascending interneurons by this insecticide will negatively impact the chances for reproduction and survival in crickets.

Ventral temporal-frontal pathways in the human brain based on diffusion MRI tractography.

The inferior colliculus (IC) integrates auditory information through a complex interplay of excitatory and inhibitory neurons, and provides both excitatory and inhibitory inputs to the medial geniculate body (MGB). Although IC projection neurons are predominantly glutamatergic, accumulating evidence suggests that they comprised heterogeneous subpopulations with distinct morphological and functional properties. Somatostatin (SST)-expressing neurons represent one such glutamatergic subpopulation; however, their characteristics and circuit organization remain poorly understood. In this study, we examined the projection domains within the MGB and the local circuits of SST-expressing neurons in the IC. SST-expressing neurons in the central nucleus of the IC (CNIC) project mainly to the ventral division of the MGB (MGv) and posterior limiting nucleus (POL), whereas those in the external (ECIC) and dorsal (DCIC) nuclei primarily target the POL. The SST axon terminals in the MGv were large, formed clusters, and positive for cholecystokinin (CCK), whereas those projecting to the POL were small, non-clustered, and CCK-negative. The local axons of SST-positive neurons in the IC formed vesicular glutamate transporter 2-positive basket-like terminals around large γ-amino butyric acid (GABA)-ergic neurons, a hallmark morphological profile of GABAergic projection neurons to the MGB. This finding indicates that SST-expressing neurons provide strong excitatory input to these inhibitory projection neurons. Collectively, our results show that IC SST-expressing neurons shape thalamic processing not only through direct excitatory inputs to the MGv and POL, but also indirectly via strong excitation of local GABAergic projection neurons, thereby positioning SST neurons as key regulators of IC-MGB communication.

The ability to integrate information from different sensory modalities, such as vision and hearing, enables us to perceive and understand complex stimuli. The relevance of this ability can be seen in speech perception, for example, which requires the integration of auditory (e.g., voice) and visual (e.g., lip movements) information. Recent studies have shown that the accuracy of this integration process, and thus speech comprehension, can be improved by brief audiovisual feedback training. However, the long-term stability as well as associated cognitive mechanisms are not yet fully understood. In the present study, we evaluated the effect of a short audiovisual feedback training on multisensory integration and speech perception using three different paradigms. Audiovisual integration was evaluated at three distinct time points: pretraining, immediately post-training and 12 days later. To investigate the relationship between training efficacy and specific cognitive abilities, participants underwent the German version of the Wechsler Adult Intelligence Scale (WAIS-IV), which assesses language comprehension, perceptional reasoning, processing speed, working memory and overall intelligence quotient. Notably, our results indicate a sustained enhancement in audiovisual integration and speech perception that persisted for up to 12 days following the training. No associations with cognitive abilities were found. The findings indicate that a brief audiovisual feedback training enables long-term improvements in multisensory integration, independent of cognitive abilities.

Immersive technologies such as 360-degree video virtual reality (360VR) provide unique opportunities to simulate representative environments to investigate decision-making in a safe and cost-effective manner. Inclusion of multi-sensory visual, contextual, and auditory information is important to enhance simulator psychological fidelity. Yet, the influence of increased sensory information on decision-making, presence, and cognitive load in 360VR compared to less immersive two-dimensional video simulators is unknown. This study investigated multi-sensory information, presence, and cognitive load across immersion conditions (360VR and two-dimensional video) in an exemplar sport-specific decision-making task. Fifteen higher-skilled and 15 lesser-skilled Australian Rules Football players completed a decision-making task which presented visual information only, visual and contextual information, and visual, contextual and auditory information. Overall, there were little significant performance difference between simulators. There was a significant decrease in decision-making performance across both skill levels and simulators as contextual and auditory information was added. Decision-making performance decline was more pronounced for lesser-skilled than higher-skilled participants, when they had to utilise contextual information to make riskier decisions to win the game. Significantly more accurate decisions were made when congruent, compared to incongruent, auditory information was presented, particularly in two-dimensional video. Perceptions of presence and cognitive load were significantly higher in 360VR than two-dimensional video, regardless of skill level, whilst across both simulators, cognitive load increased as sensory information was added. These findings indicate provision of multi-sensory information is more important for decision-making than simulator immersion and presence. Therefore, a focus on increasing simulator immersion should be done so with caution.

Speech is essential for everyday communication during the entire lifespan of an individual. Visual lip movement can support auditory speech perception, particularly in noisy environments and among older adults with hearing impairments. This study investigated whether visual information is integrated with auditory phonetic information without visual awareness and how this process changes with age. Participants heard low signal-to-noise monosyllables (/ba/, /da/, or /ga/) accompanied by visual lip movements under either visible or invisible conditions, the latter being achieved using continuous flash suppression. Three types of visual stimuli were used: incongruent (eliciting the McGurk effect), congruent, and no-lip movements. Participants identified the syllable they heard on each trial. Under continuous flash suppression, stimulus visibility was assessed via subjective reports in Experiment 1 and a four-alternative choice line localization task in Experiment 2. In both experiments, the McGurk effect was observed in both age groups under the visible conditions but only in younger adults under continuous flash suppression. These findings suggest that younger adults can integrate visual and auditory phonetic information without visual awareness, whereas this process may decline with age and be replaced by a more effortful, conscious mechanism-at least under low auditory signal-to-noise conditions. (PsycInfo Database Record (c) 2026 APA, all rights reserved).

Neuroscience Prior knowledge guided EEG representation disentanglement for auditory attention decoding.

SummaryActivity-dependent modulation of presynaptic voltage-gated Ca2+ channels (CaV2) regulates Ca2+ influx to control neuronal circuit output. Although CaV2.1 can undergo robust Ca2+ dependent facilitation (CDF), whether it occurs in native central nervous system neuronal circuits is disputed. Accurate auditory information processing requires precise and reliable synaptic transmission at high activity rates in the auditory brainstem. To determine if CaV2.1 CDF is a key regulator of high-fidelity synaptic transmission, we expressed CaV2.1 splice variants capable (CaV2.1 37a) or incapable (CaV2.1 37b) of CDF at the calyx of Held presynaptic terminal in the auditory brainstem. We found no difference in basal CaV2.1 currents or synaptic transmission. However, CaV2.1 37b terminals lacked CDF, synaptic facilitation and had a decreased reliability and precision of postsynaptic action-potential firing. Additionally, the Wave III amplitude of the auditory brainstem responses was reduced. We propose that CaV2.1 CDF is essential for accurate auditory information processing.

Lmx1a/b paralogous genes, which arose from the invertebrate Lmx1b-like gene, are critical for hearing in multiple vertebrate species, and mutations in these genes cause hearing deficits in humans. While the unique and redundant functions of Lmx1a/b in the inner ear are well established, their contribution to the development of the cochlear nuclei, which process and relay auditory information to the brain, is poorly understood. Since cochlear nuclei maturate postnatally, here we analyzed Lmx1a+/-;Lmx1b+/-, Lmx1a-/-, and Lmx1a-/-;Lmx1b+/- mice that survive past birth. Loss of Lmx1a reduced distinct populations of excitatory neurons in dorsal (DCN) and ventral (VCN) cochlear nuclei and their innervation from the inner ear. Additional loss of one Lmx1b copy made Lmx1a-/- phenotypes more severe, revealing that Lmx1b acts redundantly with Lmx1a. Unlike Lmx1a-/- mice, excitatory neurons were not affected in Lmx1a+/-;Lmx1b+/- mice. Thus, while cochlear nuclei are sensitive to Lmx1a/b gene dosage, these genes are not completely equivalent, and Lmx1a has a more profound role in cochlear nuclei development. Lmx1a-/- and especially Lmx1a-/-;Lmx1b+/- embryos had fewer Atoh1+ progenitors that produce excitatory neurons of the cochlear nuclei, and reduced Bmp6 expression in the roof plate, the signaling center that induces these progenitors via Bmp signaling. We found that Lmx1a is the primary regulator of Bmp6, whereas Lmx1b contributes only in the absence of Lmx1a. Thus, Lmx1a plays a major role in the formation of the mature structure and connectivity of both the DCV and VCN, and Lmx1b acts redundantly to Lmx1a but only partially compensates for Lmx1a loss.

Artificial intelligence (AI) chatbots based on large language models (LLMs) can deliver medical information, but their performance on specialized topics such as central auditory processing disorder (CAPD) remains unexplored. This study evaluated the accuracy and completeness of three AI chatbots (ChatGPT, Gemini, and Claude) in providing CAPD-related information across varying levels of question complexity. Forty-four questions, categorized into four difficulty levels (patient level, easy, intermediate, and specialized; n = 11 each), were submitted to each chatbot, generating 132 responses. Seven clinical experts, blinded to chatbot identity, independently rated accuracy and completeness on a 1-5 Likert scale. Data were analyzed with analyses of variance, correlations, and interrater comparisons. Chatbot performance was similar, with mean accuracy below 4.0 and completeness about 3.5. Complex questions often scored below 3.0 across experts. Only three of the 44 questions, primarily patient level or relatively simple, received consistently high expert ratings (≥ 4 for both accuracy and completeness) across all three chatbots. Performance declined with question difficulty, although differences were not statistically significant. Accuracy and completeness were correlated across chatbots. Current AI chatbots provided generally accurate CAPD information but fell short of clinical standards, particularly on specialized questions. Their limited performance underscores the need for clinician oversight in CAPD assessment and management. Chatbots may serve as helpful adjuncts but should not replace expert evaluation and guidance in clinical settings. https://doi.org/10.23641/asha.31975101.

Baseline Mismatch Negativity Amplitude Predicts Direction and Magnitude of Ketamine Effect in Healthy Volunteers - A "Disordinal" Effect.

Embodied views of language comprehension argue that the body's perceptual and motor systems ground linguistic meaning. One source of support for this view comes from the sentence-picture verification (SPV) shape match effect, in which observers read a sentence that implies - but does not explicitly describe - an object's shape and then report whether a pictured object was mentioned in the sentence. Participants are typically faster to verify a sentence mentioned an object when the object's shape matches the shape implied by that sentence's context. However, several high-profile studies have failed to replicate this and other key results supporting the sensorimotor simulation view, raising questions about the extent to which language comprehension relies upon modal representations. One explanation for these conflicting findings is that individuals do not obligatorily tap perceptual and motor systems to understand language but are instead flexible in their use of sensorimotor simulation depending upon contextual factors such as task demands. I investigated this possibility by asking participants to perform the SPV task while concurrently holding either auditory or visual information in working memory. I found that higher working memory loads in both the auditory and the visual domains attenuated the SPV match advantage. This finding suggests that sensorimotor simulation is not necessary for language comprehension but may instead depend in part upon the availability of resources in working memory.

Sensorimotor adaptation relies on the integration of multisensory feedback, yet the specific contributions of auditory signals to this process remain poorly understood compared to vision. We tested 46 participants on a reaching task using visual, auditory, or combined feedback about terminal errors. Participants alternated between feedback modalities during learning and relearning, revealing how adaptation transfers across sensory systems. Strikingly, although auditory feedback alone failed to support initial learning, prior visual learning enabled subsequent auditory adaptation. Further experiments showed that this cross-modal transfer stems from a memory of the learned reaching direction, acting as an attractor for movement, independent of error-based mechanisms, or explicit strategies. Our findings unveil a novel pathway for sensory integration in motor learning, with implications for designing cross-modal training protocols.

Remimazolam-induced dysfunction of thalamic reticular nucleus impairs auditory gating during postanaesthetic recovery in mice.

ABSTRACTNeurons that express Nps send output to brain regions implicated in circadian function and threat responses, but less is known about the afferent control of these neurons. In this study, we used a sensitive retrograde tracer, cholera toxin beta subunit (CTb), to identify afferents to the rostral–lateral parabrachial region that contains the main concentration of Nps‐expressing neurons. We then used Cre‐dependent rabies retrograde tracing in Nps‐2A‐Cre mice to identify inputs to Nps‐expressing neurons within this region. These neurons receive heavy input from auditory brainstem structures, including the inferior colliculus, ventral nucleus of the lateral lemniscus, superior olivary complex, and cochlear nucleus. Due to a discrepancy between sparse rabies and prominent CTb labeling extending from the ipsilateral insular to auditory areas of the cerebral cortex, we also performed anterograde labeling and found many close contacts between cortical boutons and Nps‐expressing neurons. These findings suggest an unexpected role for auditory information in controlling the activity of Nps‐expressing neurons and add to existing evidence suggesting that rabies is relatively insensitive to retrograde labeling of cortical afferents.

Accurate characterization of auditory pathway responses is critical for understanding neural disorders that affect hearing, including both peripheral and central deficits, as well as broader neurodevelopmental conditions. Animal models provide a way to investigate auditory circuit activation with high spatial and temporal resolution. Here, we first assessed behavioral detection of pure tones (PT) and narrowband noise (NBN) stimuli in male rats, revealing that NBN targets were detected at lower amplitudes than PT targets, consistent with human auditory detection patterns. We then compared these behavioral results with neural responses recorded in female rats' medial geniculate body (MGB), a thalamic relay to the auditory cortex. Using high-density multichannel recordings, we found that NBN stimuli elicited greater neural sensitivity at low amplitudes, whereas PT stimuli evoked faster responses and higher peak firing rates. MGB units achieved maximal frequency discrimination at amplitudes close to detection threshold, with a sharp decline at both lower and higher intensities, suggesting that neurons with lower sensitivities primarily contribute to processing at moderate to high sound levels. Decoding analyses demonstrated accurate frequency classification from MGB population activity, with PT yielding higher accuracy than NBN, highlighting the potential of multichannel recordings for precise auditory information assessment. Our results indicate that NBN and PT stimuli differentially probe auditory thalamic processing, with NBN advantageous for detecting subtle sensitivity changes and PT optimal for timing analyses. These findings advance the translational relevance of rodent models for preclinical evaluation of therapies targeting central auditory deficits.