scholarly journals Statistics of natural reverberation enable perceptual separation of sound and space

2016 ◽  
Vol 113 (48) ◽  
pp. E7856-E7865 ◽  
Author(s):  
James Traer ◽  
Josh H. McDermott

In everyday listening, sound reaches our ears directly from a source as well as indirectly via reflections known as reverberation. Reverberation profoundly distorts the sound from a source, yet humans can both identify sound sources and distinguish environments from the resulting sound, via mechanisms that remain unclear. The core computational challenge is that the acoustic signatures of the source and environment are combined in a single signal received by the ear. Here we ask whether our recognition of sound sources and spaces reflects an ability to separate their effects and whether any such separation is enabled by statistical regularities of real-world reverberation. To first determine whether such statistical regularities exist, we measured impulse responses (IRs) of 271 spaces sampled from the distribution encountered by humans during daily life. The sampled spaces were diverse, but their IRs were tightly constrained, exhibiting exponential decay at frequency-dependent rates: Mid frequencies reverberated longest whereas higher and lower frequencies decayed more rapidly, presumably due to absorptive properties of materials and air. To test whether humans leverage these regularities, we manipulated IR decay characteristics in simulated reverberant audio. Listeners could discriminate sound sources and environments from these signals, but their abilities degraded when reverberation characteristics deviated from those of real-world environments. Subjectively, atypical IRs were mistaken for sound sources. The results suggest the brain separates sound into contributions from the source and the environment, constrained by a prior on natural reverberation. This separation process may contribute to robust recognition while providing information about spaces around us.

PsycCRITIQUES ◽  
2017 ◽  
Vol 62 (44) ◽  
Author(s):  
David S. Kreiner
Keyword(s):  
The Core ◽  

2020 ◽  
Author(s):  
Stephen Charles Van Hedger ◽  
Ingrid Johnsrude ◽  
Laura Batterink

Listeners are adept at extracting regularities from the environment, a process known as statistical learning (SL). SL has been generally assumed to be a form of “context-free” learning that occurs independently of prior knowledge, and SL experiments typically involve exposing participants to presumed novel regularities, such as repeating nonsense words. However, recent work has called this assumption into question, demonstrating that learners’ previous language experience can considerably influence SL performance. In the present experiment, we tested whether previous knowledge also shapes SL in a non-linguistic domain, using a paradigm that involves extracting regularities over tone sequences. Participants learned novel tone sequences, which consisted of pitch intervals not typically found in Western music. For one group of participants, the tone sequences used artificial, computerized instrument sounds. For the other group, the same tone sequences used familiar instrument sounds (piano or violin). Knowledge of the statistical regularities was assessed using both trained sounds (measuring specific learning) and sounds that differed in pitch range and/or instrument (measuring transfer learning). In a follow-up experiment, two additional testing sessions were administered to gauge retention of learning (one day and approximately one-week post-training). Compared to artificial instruments, training on sequences played by familiar instruments resulted in reduced correlations among test items, reflecting more idiosyncratic performance. Across all three testing sessions, learning of novel regularities presented with familiar instruments was worse compared to unfamiliar instruments, suggesting that prior exposure to music produced by familiar instruments interfered with new sequence learning. Overall, these results demonstrate that real-world experience influences SL in a non-linguistic domain, supporting the view that SL involves the continuous updating of existing representations, rather than the establishment of entirely novel ones.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Marios Papachristou

AbstractIn this paper we devise a generative random network model with core–periphery properties whose core nodes act as sublinear dominators, that is, if the network has n nodes, the core has size o(n) and dominates the entire network. We show that instances generated by this model exhibit power law degree distributions, and incorporates small-world phenomena. We also fit our model in a variety of real-world networks.


2021 ◽  
Vol 9 (1) ◽  
pp. 3
Author(s):  
Shankar Rengasamy Venugopalan ◽  
Eric Van Otterloo

The cranial base is a multifunctional bony platform within the core of the cranium, spanning rostral to caudal ends. This structure provides support for the brain and skull vault above, serves as a link between the head and the vertebral column below, and seamlessly integrates with the facial skeleton at its rostral end. Unique from the majority of the cranial skeleton, the cranial base develops from a cartilage intermediate—the chondrocranium—through the process of endochondral ossification. Owing to the intimate association of the cranial base with nearly all aspects of the head, congenital birth defects impacting these structures often coincide with anomalies of the cranial base. Despite this critical importance, studies investigating the genetic control of cranial base development and associated disorders lags in comparison to other craniofacial structures. Here, we highlight and review developmental and genetic aspects of the cranial base, including its transition from cartilage to bone, dual embryological origins, and vignettes of transcription factors controlling its formation.


2013 ◽  
Vol 18 (2) ◽  
pp. 130-144 ◽  
Author(s):  
KEES DE BOT ◽  
CAROL JAENSCH

While research on third language (L3) and multilingualism has recently shown remarkable growth, the fundamental question of what makes trilingualism special compared to bilingualism, and indeed monolingualism, continues to be evaded. In this contribution we consider whether there is such a thing as a true monolingual, and if there is a difference between dialects, styles, registers and languages. While linguistic and psycholinguistic studies suggest differences in the processing of a third, compared to the first or second language, neurolinguistic research has shown that generally the same areas of the brain are activated during language use in proficient multilinguals. It is concluded that while from traditional linguistic and psycholinguistic perspectives there are grounds to differentiate monolingual, bilingual and multilingual processing, a more dynamic perspective on language processing in which development over time is the core issue, leads to a questioning of the notion of languages as separate entities in the brain.


2015 ◽  
Author(s):  
Manivannan Subramaniyan ◽  
Alexander S. Ecker ◽  
Saumil S. Patel ◽  
R. James Cotton ◽  
Matthias Bethge ◽  
...  

AbstractWhen the brain has determined the position of a moving object, due to anatomical and processing delays, the object will have already moved to a new location. Given the statistical regularities present in natural motion, the brain may have acquired compensatory mechanisms to minimize the mismatch between the perceived and the real position of a moving object. A well-known visual illusion — the flash lag effect — points towards such a possibility. Although many psychophysical models have been suggested to explain this illusion, their predictions have not been tested at the neural level, particularly in a species of animal known to perceive the illusion. Towards this, we recorded neural responses to flashed and moving bars from primary visual cortex (V1) of awake, fixating macaque monkeys. We found that the response latency to moving bars of varying speed, motion direction and luminance was shorter than that to flashes, in a manner that is consistent with psychophysical results. At the level of V1, our results support the differential latency model positing that flashed and moving bars have different latencies. As we found a neural correlate of the illusion in passively fixating monkeys, our results also suggest that judging the instantaneous position of the moving bar at the time of flash — as required by the postdiction/motion-biasing model — may not be necessary for observing a neural correlate of the illusion. Our results also suggest that the brain may have evolved mechanisms to process moving stimuli faster and closer to real time compared with briefly appearing stationary stimuli.New and NoteworthyWe report several observations in awake macaque V1 that provide support for the differential latency model of the flash lag illusion. We find that the equal latency of flash and moving stimuli as assumed by motion integration/postdiction models does not hold in V1. We show that in macaque V1, motion processing latency depends on stimulus luminance, speed and motion direction in a manner consistent with several psychophysical properties of the flash lag illusion.


2021 ◽  
Author(s):  
◽  
Timothy Sherry

<p>An online convolutive blind source separation solution has been developed for use in reverberant environments with stationary sources. Results are presented for simulation and real world data. The system achieves a separation SINR of 16.8 dB when operating on a two source mixture, with a total acoustic delay was 270 ms. This is on par with, and in many respects outperforms various published algorithms [1],[2]. A number of instantaneous blind source separation algorithms have been developed, including a block wise and recursive ICA algorithm, and a clustering based algorithm, able to obtain up to 110 dB SIR performance. The system has been realised in both Matlab and C, and is modular, allowing for easy update of the ICA algorithm that is the core of the unmixing process.</p>


2021 ◽  
Author(s):  
Yuta Katsumi ◽  
Karen Quigley ◽  
Lisa Feldman Barrett

It is now well known that brain evolution, development, and structure do not respect Western folk categories of mind – that is, the boundaries of those folk categories have never been identified in nature, despite decades of search. Categories for cognitions, emotions, perceptions, and so on, may be useful for describing the mental phenomena that constitute a human mind, but they make a poor starting point for understanding the interplay of mechanisms that create those mental events in the first place. In this paper, we integrate evolutionary, developmental, anatomical, and functional evidence and propose that predictive regulation of the body’s internal systems (allostasis) and modeling the sensory consequences of this regulation (interoception) may be basic functions of the brain that are embedded in coordinated structural and functional gradients. Our approach offers the basis for a coherent, neurobiologically-inspired research program that attempts to explain how a variety of psychological and physical phenomena may emerge from the same biological mechanisms, thus providing an opportunity to unify them under a common explanatory framework that can be used to develop shared vocabulary for theory building and knowledge accumulation.


2013 ◽  
Vol 668 ◽  
pp. 101-104
Author(s):  
Tie Liu Wang ◽  
Zhong Yi Wang ◽  
Wei Wan

The magnetic measurement stress sensor is the core of the magnetic measurement stress technology. Magnetic measurement stress sensor using magnetostriction and Giant Magneto Resistance (GMR) theory has good correspondence between stress and magnetic, and been validated scientific and reliable through indoor experiments and engineering applications. This paper gives a method on stress sensor anode calibration, verifies the different performance of the sensor based on different materials, makes an analysis of the error between the theoretical calculations and actual measurements of the standard objects, describes the working conditions of using the sensor and indicates a reasonable match is a prerequisite to obtain the desired signal processing results.


2021 ◽  
Author(s):  
Antonio Benítez-Burraco ◽  
Koji Fuita ◽  
Koji Hoshi ◽  
Ljiljana Progovac

In this Chapter we first look at the core view of the biology of language associated with Minimalism, including the Biolinguistics Program (section 2). Next, we consider research on the brain (section 3) and genetics (section 4), associated with this framework. Finally, we introduce some subsequent views of language evolution which break away from the saltationist, discontinuous nature of the mainstream approach (section 5), and draw some conclusions regarding future prospects (section 6).


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