Effects of Masking Noise on Detection Thresholds of Killer Whales

1994 ◽  
pp. 243-256 ◽  
Author(s):  
David E. Bain ◽  
Marilyn E. Dahlheim
Keyword(s):  
Killer Whales ◽  
Detection Thresholds ◽  
Masking Noise

scholarly journals Tone detection thresholds in interaurally delayed noise of different bandwidths

Acta Acustica ◽  
2021 ◽  
Vol 5 ◽  
pp. 60
Author(s):  
Mathias Dietz ◽  
Jörg Encke ◽  
Kristin I Bracklo ◽  
Stephan D Ewert
Keyword(s):  
Temporal Coherence ◽  
Delay Lines ◽  
Detection Thresholds ◽  
Filter Bandwidth ◽  
Masking Release ◽  
Interaural Phase ◽  
Significant Difference ◽  
Masking Noise ◽  
Interaural Phase Difference ◽  
Interaural Time Delay

Differences between the interaural phase of a noise and a target tone improve detection thresholds. The maximum masking release is obtained for detecting an antiphasic tone (Sπ) in diotic noise (N0). It has been shown in several studies that this benefit gradually declines as an interaural time delay (ITD) is applied to the noise. This decline has been attributed to the reduced interaural coherence of the noise. Here, we report detection thresholds for a 500 Hz tone in masking noise with ITDs up to 8 ms and bandwidths from 25 to 1000 Hz. Reducing the noise bandwidth from 100 to 50 and 25 Hz increased the masking release for 8-ms ITD, as expected for increasing temporal coherence with decreasing bandwidth. For bandwidths of 100–1000 Hz no significant difference in masking release was observed. Detection thresholds with these wider-band noises had an ITD dependence that is fully described by the temporal coherence imposed by the typical monaurally determined auditory-filter bandwidth. A binaural model based on interaural phase-difference fluctuations accounts for the data without using delay lines.

scholarly journals Ecological validity of masking release with speech-like stimuli

2021 ◽  
Author(s):  
Hyojin Kim ◽  
Viktorija Ratkute ◽  
Bastian Epp
Keyword(s):  
Speech Perception ◽  
Temporal Dynamics ◽  
Ecological Validity ◽  
Detection Thresholds ◽  
Formant Frequencies ◽  
Masking Release ◽  
Grouping Effect ◽  
Masking Level Difference ◽  
Masking Noise ◽  
Comodulation Masking Release

Comodulated masking noise and binaural cues can facilitate detecting a target sound from noise. These cues can induce a decrease in detection thresholds, quantified as comodulation masking release (CMR) and binaural masking level difference (BMLD), respectively. However, their relevance to speech perception is unclear as most studies have used artificial stimuli different from speech. Here, we investigated their ecological validity using sounds with speech-like spectro-temporal dynamics. We evaluated the ecological validity of such grouping effect with stimuli reflecting formant changes in speech. We set three masker bands at formant frequencies F1, F2, and F3 based on CV combination: /gu/, /fu/, and /pu/. We found that the CMR was little (< 3 dB) while BMLD was comparable to previous findings (~ 9 dB). In conclusion, we suggest that other features may play a role in facilitating frequency grouping by comodulation such as the spectral proximity and the number of masker bands.

scholarly journals The effect of the preceding masking noise on monaural and binaural release from masking

2021 ◽  
Author(s):  
Hyojin Kim ◽  
Viktorija Ratkute ◽  
Bastian Epp
Keyword(s):  
Cochlear Nucleus ◽  
Temporal Integration ◽  
System Level ◽  
Top Down ◽  
Detection Thresholds ◽  
Masking Release ◽  
Masking Level Difference ◽  
Masking Noise ◽  
Comodulation Masking Release ◽  
Release From Masking

When a target tone is preceded by a noise, the threshold for target detection can be increased or decreased depending on the type of a preceding masker. The effect of preceding masker to the following sound can be interpreted as either the result of adaptation at the periphery or at the system level. To disentangle these, we investigated the time constant of adaptation by varying the length of the preceding masker. For inducing various masking conditions, we designed stimuli that can induce masking release. Comodulated masking noise and binaural cues can facilitate detecting a target sound from noise. These cues induce a decrease in detection thresholds, quantified as comodulation masking release (CMR) and binaural masking level difference (BMLD), respectively. We hypothesized that if the adaptation results from the top-down processing, both CMR and BMLD will be affected with increased length of the preceding masker. We measured CMR and BMLD when the length of preceding maskers varied from 0 (no preceding masker) to 500 ms. Results showed that CMR was more affected with longer preceding masker from 100 ms to 500 ms while the preceding masker did not affect BMLD. In this study, we suggest that the adaptation to preceding masking sound may arise from low level (e.g. cochlear nucleus, CN) rather than the temporal integration by the higher-level processing.

Personality in captive killer whales (Orcinus orca): A rating approach based on the five-factor model.

2019 ◽  
Vol 133 (2) ◽  
pp. 252-261 ◽  
Author(s):  
Yulán Úbeda ◽  
Sara Ortín ◽  
Judy St. Leger ◽  
Miquel Llorente ◽  
Javier Almunia
Keyword(s):  
Factor Model ◽  
Five Factor Model ◽  
Orcinus Orca ◽  
Killer Whales

Analysis and Identification of Off-Odor Compounds in Electronic Systems

2006 ◽  
Author(s):  
Mary Ann Nailos ◽  
Dan Stein ◽  
Lawrence T. Nielsen ◽  
Anna Iwasinska
Keyword(s):  
Volatile Compounds ◽  
Electronic Systems ◽  
Detection Thresholds ◽  
Detection And Identification ◽  
Odor Compounds ◽  
Novel Method ◽  
Odor Analysis ◽  
Analytical System ◽  
Task Perception ◽  
Analytical Tools

Abstract The detection and identification of substances that give rise to aromas and off-odors is often a difficult task. Perception of odors is very subjective and odor detection thresholds vary from person to person. The identification of trace levels of compounds responsible for perceived odors is difficult using conventional analytical tools. This paper will focus on a novel method for sampling and analyzing aromatic volatile compounds using an analytical system specifically designed for odor analysis.

Olfactometric characterisation of sludge odours

2000 ◽  
Vol 41 (6) ◽  
pp. 49-55 ◽  
Author(s):  
S. D. Lambert ◽  
A. L. Beaman ◽  
P. Winter
Keyword(s):  
Recent Work ◽  
Sewage Treatment ◽  
Limited Information ◽  
Hedonic Tone ◽  
Detection Thresholds ◽  
Remediation Measures ◽  
Odour Concentration ◽  
Odour Profile ◽  
Storage Facilities

Conventional olfactometric techniques have been used to evaluate odours from sewage treatment and sludge storage facilities primarily in terms of odour concentration relative to their detection thresholds. However, such data conveys limited information that would be useful for determining the causes of most odours or the most appropriate remediation measures to be taken. Thispaper discusses some recent work undertaken to characterise the olfactometric profiles of different odours. Standard descriptive terms were used to characterise odours at normalised, moderately strong concentrations. These were used directly for the calculation of hedonic tone. They were also collated into a small number of generic odour groups and plotted to allow visual comparisons of different odour profile fingerprints. Such odour characterisations have proved to be very useful and may easily be incorporated into normal olfactometric evaluations.

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