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Auditory stream segregation using amplitude modulated bandpass noise.

Nie Y, Nelson PB - Front Psychol (2015)

Bottom Line: Long and short sequences were studied to investigate the build-up effect for segregation based on spectral and AM-rate differences.Results showed the following: (1).Based on the spectral differences, listeners can segregate auditory streams better as the listening duration is prolonged-i.e., sparse spectral cues elicit build-up segregation; however, AM-rate differences only appear to elicit build-up when in combination with spectral difference cues.

View Article: PubMed Central - PubMed

Affiliation: Department of Communication Sciences and Disorders, James Madison University Harrisonburg, VA, USA.

ABSTRACT
The purpose of this study was to investigate the roles of spectral overlap and amplitude modulation (AM) rate for stream segregation for noise signals, as well as to test the build-up effect based on these two cues. Segregation ability was evaluated using an objective paradigm with listeners' attention focused on stream segregation. Stimulus sequences consisted of two interleaved sets of bandpass noise bursts (A and B bursts). The A and B bursts differed in spectrum, AM-rate, or both. The amount of the difference between the two sets of noise bursts was varied. Long and short sequences were studied to investigate the build-up effect for segregation based on spectral and AM-rate differences. Results showed the following: (1). Stream segregation ability increased with greater spectral separation. (2). Larger AM-rate separations were associated with stronger segregation abilities. (3). Spectral separation was found to elicit the build-up effect for the range of spectral differences assessed in the current study. (4). AM-rate separation interacted with spectral separation suggesting an additive effect of spectral separation and AM-rate separation on segregation build-up. The findings suggest that, when normal-hearing listeners direct their attention towards segregation, they are able to segregate auditory streams based on reduced spectral contrast cues that vary by the amount of spectral overlap. Further, regardless of the spectral separation they are able to use AM-rate difference as a secondary/weaker cue. Based on the spectral differences, listeners can segregate auditory streams better as the listening duration is prolonged-i.e., sparse spectral cues elicit build-up segregation; however, AM-rate differences only appear to elicit build-up when in combination with spectral difference cues.

No MeSH data available.


Related in: MedlinePlus

Illustration of the stimulus paradigm (modified from Nie et al., 2014). (A,B) Illustrate the delayed sequences with the dark solid lines showing the duration of the delay for the last B burst. (C,D) Illustrate the no-delay sequences. (A,C) Depict the integrated perception and (B,D) depict the segregated perception. The spectral conditions for A and B bursts are A678 and B1234, respectively. The AM rates shown on the A bursts and B bursts are 25 and 300 Hz, respectively.
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Figure 1: Illustration of the stimulus paradigm (modified from Nie et al., 2014). (A,B) Illustrate the delayed sequences with the dark solid lines showing the duration of the delay for the last B burst. (C,D) Illustrate the no-delay sequences. (A,C) Depict the integrated perception and (B,D) depict the segregated perception. The spectral conditions for A and B bursts are A678 and B1234, respectively. The AM rates shown on the A bursts and B bursts are 25 and 300 Hz, respectively.

Mentions: Two types of stimulus sequences were adopted differing in the placement of the last B burst as illustrated in Figure 1. In a delayed sequence, the last B burst was delayed from its nominal temporal position by 30 ms, whereas, in a no-delay sequence, the last B burst was advanced by an amount drawn randomly on each presentation from a rectangular distribution ranging from 0 to 10 ms. The total duration was 3.1 s for the delayed sequences and 3.06–3.07 s for the no-delay sequences.


Auditory stream segregation using amplitude modulated bandpass noise.

Nie Y, Nelson PB - Front Psychol (2015)

Illustration of the stimulus paradigm (modified from Nie et al., 2014). (A,B) Illustrate the delayed sequences with the dark solid lines showing the duration of the delay for the last B burst. (C,D) Illustrate the no-delay sequences. (A,C) Depict the integrated perception and (B,D) depict the segregated perception. The spectral conditions for A and B bursts are A678 and B1234, respectively. The AM rates shown on the A bursts and B bursts are 25 and 300 Hz, respectively.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4528102&req=5

Figure 1: Illustration of the stimulus paradigm (modified from Nie et al., 2014). (A,B) Illustrate the delayed sequences with the dark solid lines showing the duration of the delay for the last B burst. (C,D) Illustrate the no-delay sequences. (A,C) Depict the integrated perception and (B,D) depict the segregated perception. The spectral conditions for A and B bursts are A678 and B1234, respectively. The AM rates shown on the A bursts and B bursts are 25 and 300 Hz, respectively.
Mentions: Two types of stimulus sequences were adopted differing in the placement of the last B burst as illustrated in Figure 1. In a delayed sequence, the last B burst was delayed from its nominal temporal position by 30 ms, whereas, in a no-delay sequence, the last B burst was advanced by an amount drawn randomly on each presentation from a rectangular distribution ranging from 0 to 10 ms. The total duration was 3.1 s for the delayed sequences and 3.06–3.07 s for the no-delay sequences.

Bottom Line: Long and short sequences were studied to investigate the build-up effect for segregation based on spectral and AM-rate differences.Results showed the following: (1).Based on the spectral differences, listeners can segregate auditory streams better as the listening duration is prolonged-i.e., sparse spectral cues elicit build-up segregation; however, AM-rate differences only appear to elicit build-up when in combination with spectral difference cues.

View Article: PubMed Central - PubMed

Affiliation: Department of Communication Sciences and Disorders, James Madison University Harrisonburg, VA, USA.

ABSTRACT
The purpose of this study was to investigate the roles of spectral overlap and amplitude modulation (AM) rate for stream segregation for noise signals, as well as to test the build-up effect based on these two cues. Segregation ability was evaluated using an objective paradigm with listeners' attention focused on stream segregation. Stimulus sequences consisted of two interleaved sets of bandpass noise bursts (A and B bursts). The A and B bursts differed in spectrum, AM-rate, or both. The amount of the difference between the two sets of noise bursts was varied. Long and short sequences were studied to investigate the build-up effect for segregation based on spectral and AM-rate differences. Results showed the following: (1). Stream segregation ability increased with greater spectral separation. (2). Larger AM-rate separations were associated with stronger segregation abilities. (3). Spectral separation was found to elicit the build-up effect for the range of spectral differences assessed in the current study. (4). AM-rate separation interacted with spectral separation suggesting an additive effect of spectral separation and AM-rate separation on segregation build-up. The findings suggest that, when normal-hearing listeners direct their attention towards segregation, they are able to segregate auditory streams based on reduced spectral contrast cues that vary by the amount of spectral overlap. Further, regardless of the spectral separation they are able to use AM-rate difference as a secondary/weaker cue. Based on the spectral differences, listeners can segregate auditory streams better as the listening duration is prolonged-i.e., sparse spectral cues elicit build-up segregation; however, AM-rate differences only appear to elicit build-up when in combination with spectral difference cues.

No MeSH data available.


Related in: MedlinePlus