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Journal of the Association For Research... Feb 2015In ordinary listening environments, acoustic signals reaching the ears directly from real sound sources are followed after a few milliseconds by early reflections... (Review)
Review
In ordinary listening environments, acoustic signals reaching the ears directly from real sound sources are followed after a few milliseconds by early reflections arriving from nearby surfaces. Early reflections are spectrotemporally similar to their source signals but commonly carry spatial acoustic cues unrelated to the source location. Humans and many other animals, including nonmammalian and even invertebrate animals, are nonetheless able to effectively localize sound sources in such environments, even in the absence of disambiguating visual cues. Robust source localization despite concurrent or nearly concurrent spurious spatial acoustic information is commonly attributed to an assortment of perceptual phenomena collectively termed "the precedence effect," characterizing the perceptual dominance of spatial information carried by the first-arriving signal. Here, we highlight recent progress and changes in the understanding of the precedence effect and related phenomena.
Topics: Animals; Humans; Psychoacoustics; Sound Localization
PubMed: 25479823
DOI: 10.1007/s10162-014-0496-2 -
The Journal of the Acoustical Society... Mar 2014Although many studies have examined the precedence effect (PE), few have tested whether it shows a buildup and breakdown in nonhuman animals comparable to that seen in... (Comparative Study)
Comparative Study
Although many studies have examined the precedence effect (PE), few have tested whether it shows a buildup and breakdown in nonhuman animals comparable to that seen in humans. These processes are thought to reflect the ability of the auditory system to adjust to a listener's acoustic environment, and their mechanisms are still poorly understood. In this study, ferrets were trained on a two-alternative forced-choice task to discriminate the azimuthal direction of brief sounds. In one experiment, pairs of noise bursts were presented from two loudspeakers at different interstimulus delays (ISDs). Results showed that localization performance changed as a function of ISD in a manner consistent with the PE being operative. A second experiment investigated buildup and breakdown of the PE by measuring the ability of ferrets to discriminate the direction of a click pair following presentation of a conditioning train. Human listeners were also tested using this paradigm. In both species, performance was better when the test clicks and conditioning train had the same ISD but deteriorated following a switch in the direction of the leading and lagging sounds between the conditioning train and test clicks. These results suggest that ferrets, like humans, experience a buildup and breakdown of the PE.
Topics: Acoustic Stimulation; Adult; Animals; Audiometry; Auditory Pathways; Behavior, Animal; Conditioning, Psychological; Discrimination, Psychological; Female; Ferrets; Humans; Male; Models, Animal; Psychoacoustics; Reaction Time; Sound Localization; Species Specificity; Time Factors
PubMed: 24606278
DOI: 10.1121/1.4864486 -
The Journal of Neuroscience : the... Oct 2019Natural sounds such as vocalizations often have covarying acoustic attributes, resulting in redundancy in neural coding. The efficient coding hypothesis proposes that...
Natural sounds such as vocalizations often have covarying acoustic attributes, resulting in redundancy in neural coding. The efficient coding hypothesis proposes that sensory systems are able to detect such covariation and adapt to reduce redundancy, leading to more efficient neural coding. Recent psychoacoustic studies have shown the auditory system can rapidly adapt to efficiently encode two covarying dimensions as a single dimension, following passive exposure to sounds in which temporal and spectral attributes covaried in a correlated fashion. However, these studies observed a cost to this adaptation, which was a loss of sensitivity to the orthogonal dimension. Here we explore the neural basis of this psychophysical phenomenon by recording single-unit responses from the primary auditory cortex in awake ferrets exposed passively to stimuli with two correlated attributes, similar in stimulus design to the psychoacoustic experiments in humans. We found: (1) the signal-to-noise ratio of spike-rate coding of cortical responses driven by sounds with correlated attributes remained unchanged along the exposure dimension, but was reduced along the orthogonal dimension; (2) performance of a decoder trained with spike data to discriminate stimuli along the orthogonal dimension was equally reduced; (3) correlations between neurons tuned to the two covarying attributes decreased after exposure; and (4) these exposure effects still occurred if sounds were correlated along two acoustic dimensions, but varied randomly along a third dimension. These neurophysiological results are consistent with the efficient coding hypothesis and may help deepen our understanding of how the auditory system encodes and represents acoustic regularities and covariance. The efficient coding (EC) hypothesis (Attneave, 1954; Barlow, 1961) proposes that the neural code in sensory systems efficiently encodes natural stimuli by minimizing the number of spikes to transmit a sensory signal. Results of recent psychoacoustic studies in humans are consistent with the EC hypothesis in that, following passive exposure to stimuli with correlated attributes, the auditory system rapidly adapts so as to more efficiently encode the two covarying dimensions as a single dimension. In the current neurophysiological experiments, using a similar stimulus design and the experimental paradigm to the psychoacoustic studies of Stilp et al. (2010) and Stilp and Kluender (2011, 2012, 2016), we recorded responses from single neurons in the auditory cortex of the awake ferret, showing adaptive efficient neural coding of two correlated acoustic attributes.
Topics: Acoustic Stimulation; Action Potentials; Adaptation, Physiological; Animals; Auditory Cortex; Auditory Perception; Female; Ferrets; Models, Neurological; Neurons; Psychoacoustics
PubMed: 31519821
DOI: 10.1523/JNEUROSCI.0141-19.2019 -
The Journal of the Acoustical Society... Apr 2017The efficient measurement of the threshold and slope of the psychometric function (PF) is an important objective in psychoacoustics. This paper proposes a procedure that...
The efficient measurement of the threshold and slope of the psychometric function (PF) is an important objective in psychoacoustics. This paper proposes a procedure that combines a Bayesian estimate of the PF with either a look one-ahead or a look two-ahead method of selecting the next stimulus presentation. The procedure differs from previously proposed algorithms in two respects: (i) it does not require the range of possible PF parameters to be specified in advance and (ii) the sequence of probe signal-to-noise ratios optimizes the threshold and slope estimates at a performance level, ϕ, that can be chosen by the experimenter. Simulation results show that the proposed procedure is robust and that the estimates of both threshold and slope have a consistently low bias. Over a wide range of listener PF parameters, the root-mean-square errors after 50 trials were ∼1.2 dB in threshold and 0.14 in log-slope. It was found that the performance differences between the look one-ahead and look two-ahead methods were negligible and that an entropy-based criterion for selecting the next stimulus was preferred to a variance-based criterion.
Topics: Acoustic Stimulation; Algorithms; Bayes Theorem; Computer Simulation; Humans; Monte Carlo Method; Psychoacoustics; Speech Intelligibility; Speech Perception; Speech Reception Threshold Test
PubMed: 28464623
DOI: 10.1121/1.4979580 -
Current Opinion in Neurobiology Aug 2008The perception of music depends on many culture-specific factors, but is also constrained by properties of the auditory system. This has been best characterized for... (Review)
Review
The perception of music depends on many culture-specific factors, but is also constrained by properties of the auditory system. This has been best characterized for those aspects of music that involve pitch. Pitch sequences are heard in terms of relative as well as absolute pitch. Pitch combinations give rise to emergent properties not present in the component notes. In this review we discuss the basic auditory mechanisms contributing to these and other perceptual effects in music.
Topics: Acoustic Stimulation; Animals; Auditory Perception; Brain; Humans; Music; Pitch Discrimination; Pitch Perception; Psychoacoustics; Sound
PubMed: 18824100
DOI: 10.1016/j.conb.2008.09.005 -
Scientific Reports May 2021Information integration is considered a hallmark of human consciousness. Recent research has challenged this tenet by showing multisensory interactions in the absence of...
Information integration is considered a hallmark of human consciousness. Recent research has challenged this tenet by showing multisensory interactions in the absence of awareness. This psychophysics study assessed the impact of spatial and semantic correspondences on audiovisual binding in the presence and absence of visual awareness by combining forward-backward masking with spatial ventriloquism. Observers were presented with object pictures and synchronous sounds that were spatially and/or semantically congruent or incongruent. On each trial observers located the sound, identified the picture and rated the picture's visibility. We observed a robust ventriloquist effect for subjectively visible and invisible pictures indicating that pictures that evade our perceptual awareness influence where we perceive sounds. Critically, semantic congruency enhanced these visual biases on perceived sound location only when the picture entered observers' awareness. Our results demonstrate that crossmodal influences operating from vision to audition and vice versa are interactively controlled by spatial and semantic congruency in the presence of awareness. However, when visual processing is disrupted by masking procedures audiovisual interactions no longer depend on semantic correspondences.
Topics: Acoustic Stimulation; Adult; Auditory Perception; Female; Humans; Male; Middle Aged; Psychoacoustics; Semantics; Space Perception; Visual Perception; Young Adult
PubMed: 34035358
DOI: 10.1038/s41598-021-90183-w -
Brain Research Mar 2022Attention is a crucial component in sound source segregation allowing auditory objects of interest to be both singled out and held in focus. Our study utilizes a...
Attention is a crucial component in sound source segregation allowing auditory objects of interest to be both singled out and held in focus. Our study utilizes a fundamental paradigm for sound source segregation: a sequence of interleaved tones, A and B, of different frequencies that can be heard as a single integrated stream or segregated into two streams (auditory streaming paradigm). We focus on the irregular alternations between integrated and segregated that occur for long presentations, so-called auditory bistability. Psychaoustic experiments demonstrate how attentional control, a listener's intention to experience integrated or segregated, biases perception in favour of different perceptual interpretations. Our data show that this is achieved by prolonging the dominance times of the attended percept and, to a lesser extent, by curtailing the dominance times of the unattended percept, an effect that remains consistent across a range of values for the difference in frequency between A and B. An existing neuromechanistic model describes the neural dynamics of perceptual competition downstream of primary auditory cortex (A1). The model allows us to propose plausible neural mechanisms for attentional control, as linked to different attentional strategies, in a direct comparison with behavioural data. A mechanism based on a percept-specific input gain best accounts for the effects of attentional control.
Topics: Adult; Attention; Auditory Perception; Female; Humans; Male; Models, Theoretical; Psychoacoustics
PubMed: 34785256
DOI: 10.1016/j.brainres.2021.147720 -
PloS One 2019Good hearing is a fundamental skill that allows children to develop properly, both socially and intellectually. In contrast to defects in inner ear function, however,...
BACKGROUND
Good hearing is a fundamental skill that allows children to develop properly, both socially and intellectually. In contrast to defects in inner ear function, however, auditory processing disorders (APDs)-which can affect up to 2-3% of school-children-are not easily identified with basic screening programs and must be diagnosed using special tests. Although such psychoacoustic tests are available, the scores achieved depend highly on the social, cultural, and linguistic characteristics of the population, and norms must be established for each population separately. Reference values are still lacking for the Polish population, especially for children in school-age, so that practitioners must interpret test scores themselves, often intuitively or using potentially biased thresholds from other countries.
MATERIALS AND METHODS
We investigated a sample of 94 Polish schoolchildren with normal hearing, divided into four age groups: from 7 years-olds to 10 years-olds. All children had no speech or language development disorder, learning problem, or symptom of APD. Participants were volunteers who had previously taken part in a large screening study. The group consisted of 56 girls (60%) and 38 boys (40%) with an average age of 8.6 years (SD = 1.1). The test battery included the Duration Pattern Test (DPT), Frequency Pattern Test (FPT), Time-Compressed Speech Test (CST), and Dichotic Digit Test (DDT).
RESULTS
The scores on all tests increased consistently with age. The difference between each age-group for DPT, CST, and left- and right-ear DDT tests was significant (Kruskal-Wallis test, p-values = 0.002, 0.006, 0.005, 0.020, respectively), but the effect of age on the FPT test was not (p-value = 0.143). The analysis showed a clear and significant separation between a merged group of ages 7 and 8 and another of ages 9 and 10. We, therefore, propose, for each test, separate reference values for these two particular age-groups. Using thresholds based on a 10% quantile, we offer the following reference values for ages 7-8 and 9-10 respectively: DPT, 28.5% and 53.8%; FPT, 18.5% and 27.5%; CST, 68.6% and 77.2%; left-ear DDT, 34.3% and 52.5%; right-ear DDT, 56% and 72.5%.
CONCLUSION
The scores on psychoacoustic tests to diagnose APD differ between cultures and linguistic backgrounds. Clinicians should, therefore, use norms that have been designed for the population most similar to their patients. Here, we report the use of a test battery designed for the Polish language that accounts for various aspects of APD when screening school children. Together with a full methodology of those tests, we provide norms that can be used as cut-offs in clinical diagnosis. Practitioners are invited to use them to obtain more accurate, evidence-based decisions.
Topics: Child; Female; Humans; Male; Poland; Psychoacoustics; Reference Values; Regression Analysis; Schools
PubMed: 31461473
DOI: 10.1371/journal.pone.0221689 -
International Journal of Environmental... Mar 2022Novel electric air transportation is emerging as an industry that could help to improve the lives of people living in both metropolitan and rural areas through...
Novel electric air transportation is emerging as an industry that could help to improve the lives of people living in both metropolitan and rural areas through integration into infrastructure and services. However, as this new resource of accessibility increases in momentum, the need to investigate any potential adverse health impacts on the public becomes paramount. This paper details research investigating the effectiveness of available noise metrics and sound quality metrics (SQMs) for assessing perception of drone noise. A subjective experiment was undertaken to gather data on human response to a comprehensive set of drone sounds and to investigate the relationship between perceived annoyance, perceived loudness and perceived pitch and key psychoacoustic factors. Based on statistical analyses, subjective models were obtained for perceived annoyance, loudness and pitch of drone noise. These models provide understanding on key psychoacoustic features to consider in decision making in order to mitigate the impact of drone noise. For the drone sounds tested in this paper, the main contributors to perceived annoyance are perceived noise level (PNL) and sharpness; for perceived loudness are PNL and fluctuation strength; and for perceived pitch are sharpness, roughness and Aures tonality. Responses for the drone sounds tested were found to be highly sensitive to the distance between drone and receiver, measured in terms of height above ground level (HAGL). All these findings could inform the optimisation of drone operating conditions in order to mitigate community noise.
Topics: Benchmarking; Humans; Loudness Perception; Noise; Psychoacoustics; Unmanned Aerial Devices
PubMed: 35328839
DOI: 10.3390/ijerph19063152 -
International Journal of Environmental... Dec 2022In audiovisual contexts, different conventions determine the level at which background music is mixed into the final program, and sometimes, the mix renders the music to...
In audiovisual contexts, different conventions determine the level at which background music is mixed into the final program, and sometimes, the mix renders the music to be practically or totally inaudible. From a perceptual point of view, the audibility of music is subject to auditory masking by other aural stimuli such as voice or additional sounds (e.g., applause, laughter, horns), and is also influenced by the visual content that accompanies the soundtrack, and by attentional and motivational factors. This situation is relevant to the music industry because, according to some copyright regulations, the non-audible background music must not generate any distribution rights, and the marginally audible background music must generate half of the standard value of audible music. In this study, we conduct two psychoacoustic experiments to identify several factors that influence background music perception, and their contribution to its variable audibility. Our experiments are based on auditory detection and chronometric tasks involving keyboard interactions with original TV content. From the collected data, we estimated a sound-to-music ratio range to define the audibility threshold limits of the class. In addition, results show that perception is affected by loudness level, listening condition, music sensitivity, and type of television content.
Topics: Music; Acoustic Stimulation; Auditory Perception; Sound; Psychoacoustics
PubMed: 36612443
DOI: 10.3390/ijerph20010123