scholarly journals Properties of auditory stream formation

2012 ◽  
Vol 367 (1591) ◽  
pp. 919-931 ◽  
Author(s):  
Brian C. J. Moore ◽  
Hedwig E. Gockel
Keyword(s):  
Temporal Pattern ◽  
Sudden Change ◽  
Phase Spectrum ◽  
Stream Segregation ◽  
Multiple Streams ◽  
Auditory Stream ◽  
Peripheral Auditory System ◽  
Stream Formation ◽  
Over Time ◽  
Frequency Phase

A sequence of sounds may be heard as coming from a single source (called fusion or coherence) or from two or more sources (called fission or stream segregation). Each perceived source is called a ‘stream’. When the differences between successive sounds are very large, fission nearly always occurs, whereas when the differences are very small, fusion nearly always occurs. When the differences are intermediate in size, the percept often ‘flips’ between one stream and multiple streams, a property called ‘bistability’. The flips do not generally occur regularly in time. The tendency to hear two streams builds up over time, but can be partially or completely reset by a sudden change in the properties of the sequence or by switches in attention. Stream formation depends partly on the extent to which successive sounds excite different ‘channels’ in the peripheral auditory system. However, other factors can play a strong role; multiple streams may be heard when successive sounds are presented to the same ear and have essentially identical excitation patterns in the cochlea. Differences between successive sounds in temporal envelope, fundamental frequency, phase spectrum and lateralization can all induce a percept of multiple streams. Regularities in the temporal pattern of elements within a stream can help in stabilizing that stream.

Primary Auditory Stream Segregation of Repeated Word Sequences

1976 ◽  
Vol 42 (3_suppl) ◽  
pp. 1071-1074 ◽  
Author(s):  
Betty Tuller ◽  
James R. Lackner
Keyword(s):  
Spatial Separation ◽  
Repeated Sequences ◽  
Stream Segregation ◽  
Natural Speech ◽  
Auditory Stream ◽  
Auditory Stream Segregation ◽  
Repeated Word ◽  
Auditory Sequence ◽  
Constituent Order

Primary auditory stream segregation, the perceptual segregation of acoustically related elements within a continuous auditory sequence into distinct spatial streams, prevents subjects from resolving the relative constituent order of repeated sequences of tones (Bregman & Campbell, 1971) or repeated sequences of consonant and vowel sounds (Lackner & Goldstein, 1974). To determine why primary auditory stream segregation does not interfere with the resolution of natural speech, 8 subjects were required to indicate the degree of stream segregation undergone by 24 repeated sequences of English monosyllables which varied in terms of the degrees of syntactic and intonational structure present. All sequences underwent primary auditory stream segregation to some extent but the amount of apparent spatial separation was less when syntactic and intonational structure was present.

scholarly journals Temporal coherence versus harmonicity in auditory stream formation

2013 ◽  
Vol 133 (3) ◽  
pp. EL188-EL194 ◽  
Author(s):  
Christophe Micheyl ◽  
Heather Kreft ◽  
Shihab Shamma ◽  
Andrew J. Oxenham
Keyword(s):  
Temporal Coherence ◽  
Auditory Stream ◽  
Stream Formation

scholarly journals Temporal Dynamics of Cloacal Microbiota in Adult Laying Chickens With and Without Access to an Outdoor Range

2021 ◽  
Vol 11 ◽  
Author(s):  
Janneke Schreuder ◽  
Francisca C. Velkers ◽  
Alex Bossers ◽  
Ruth J. Bouwstra ◽  
Willem F. de Boer ◽  
...  
Keyword(s):  
Microbial Community ◽  
Community Composition ◽  
Intestinal Microbiota ◽  
Environmental Changes ◽  
Temporal Dynamics ◽  
Microbial Community Composition ◽  
Sudden Change ◽  
Rrna Gene ◽  
Poultry House ◽  
Over Time

Associations between animal health and performance, and the host’s microbiota have been recently established. In poultry, changes in the intestinal microbiota have been linked to housing conditions and host development, but how the intestinal microbiota respond to environmental changes under farm conditions is less well understood. To gain insight into the microbial responses following a change in the host’s immediate environment, we monitored four indoor flocks of adult laying chickens three times over 16 weeks, during which two flocks were given access to an outdoor range, and two were kept indoors. To assess changes in the chickens’ microbiota over time, we collected cloacal swabs of 10 hens per flock and performed 16S rRNA gene amplicon sequencing. The poultry house (i.e., the stable in which flocks were housed) and sampling time explained 9.2 and 4.4% of the variation in the microbial community composition of the flocks, respectively. Remarkably, access to an outdoor range had no detectable effect on microbial community composition, the variability of microbiota among chickens of the same flock, or microbiota richness, but the microbiota of outdoor flocks became more even over time. Fluctuations in the composition of the microbiota over time within each poultry house were mainly driven by turnover in rare, rather than dominant, taxa and were unique for each flock. We identified 16 amplicon sequence variants that were differentially abundant over time between indoor and outdoor housed chickens, however none were consistently higher or lower across all chickens of one housing type over time. Our study shows that cloacal microbiota community composition in adult layers is stable following a sudden change in environment, and that temporal fluctuations are unique to each flock. By exploring microbiota of adult poultry flocks within commercial settings, our study sheds light on how the chickens’ immediate environment affects the microbiota composition.

scholarly journals Evaluation of auditory stream segregation in individuals with cochlear pathology and auditory neuropathy spectrum disorder

2021 ◽  
Author(s):  
Neha Banerjee ◽  
Prashanth Prabhu
Keyword(s):  
Profile Analysis ◽  
Auditory Scene Analysis ◽  
Auditory Neuropathy ◽  
Stream Segregation ◽  
Control Group ◽  
Spectral Profile ◽  
Auditory Stream ◽  
Auditory Stream Segregation ◽  
Cochlear Pathology ◽  
Auditory Scene

Background and Aim: The central auditory nervous system has the ability to perceptually group similar sounds and segregates different sounds called auditory stream segregation or auditory streaming or auditory scene analysis. Identification of a change in spectral profile when the amplitude of a component of complex tone is changed is referred to as Spectral profile analysis. It serves as an important cue in auditory stream segregation as the spectra of the sound source vary. The aim of the study was to assess auditory stream segregation in individuals with cochlear pathology (CP) and auditory neuropathy spectrum disorder. Methods: In the present study, three groups of participants were included. Experimental groups included 21 ears in each group with cochlear hearing loss or auditory neuropathy spectrum disorders (ANSD) and control group with 21 ears with normal hearing. Profile analysis was asse­ssed using "mlp" toolbox, which implements a maximum likelihood procedure in MATLAB. It was assessed at four frequencies (250 Hz, 500 Hz, 750 Hz, and 1000 Hz) for all three groups. Results: The results of the study indicate that the profile analysis threshold (at all four frequ­encies) was significantly poorer for individuals with CP or ANSD compared to the control group. Although, cochlear pathology group performed better than ANSD group. Conclusion: This could be because of poor spec­tral and temporal processing due to loss of outer hair cells at the level of the basilar membrane in cochlear pathology patients and due to the demyelination of auditory neurons in individuals with ANSD. Keywords: Auditory stream segregation; auditory scene analysis; spectral profiling; spectral profile analysis; cochlear pathology; auditory neuropathy spectrum disorders

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