Masking between Spatially Separated Sounds

1992 ◽  
Vol 36 (3) ◽  
pp. 253-257
Author(s):  
Michael D. Good ◽  
Robert H. Gilkey
Keyword(s):  
Free Field ◽  
Three Dimensional ◽  
Frontal Plane ◽  
Spatial Separation ◽  
Median Plane ◽  
Sound Sources ◽  
Auditory Displays ◽  
Spectral Cues ◽  
Masking Release ◽  
Release From Masking

The development of optimal three-dimensional auditory displays requires a more complete understanding of the interactions among spatially separated sounds. Free-field masking was investigated as a function of the spatial separation between signal and masker sounds within the horizontal, frontal, and median planes. The detectability of filtered pulse trains in the presence of noise maskers was measured using a cued, two-alternative, forced-choice, adaptive staircase procedure. Signal and masker combinations in low (below 2.3 kHz), middle (1.0–8.5 kHz), and high (above 3.5 kHz) frequency regions were examined. As the sound sources were separated within the horizontal plane, signal detectability increased dramatically. Similar improvement in detectability was observed within the frontal plane. As suggested by traditional binaural models, interaural time cues and interaural intensity cues are likely to play a major role in mediating masking release in both the horizontal and frontal planes. Because no interaural cues exist for stimuli presented within the median plane, traditional models would not predict a release from masking when the stimuli are separated within this plane. However, with high frequency signals, masking release similar to that observed in the horizontal and frontal planes could be observed in the median plane. The current literature suggests that sound localization in the median plane may depend on direction-specific spectral cues that are introduced by the pinna at high frequencies. The masking release observed here may also depend on these “pinna cues.”

Masking in Three-Dimensional Auditory Displays

1992 ◽  
Vol 34 (3) ◽  
pp. 255-265 ◽  
Author(s):  
Theodore J. Doll ◽  
Thomas E. Hanna ◽  
Joseph S. Russotti
Keyword(s):  
Head Movement ◽  
Signal To Noise Ratio ◽  
Free Field ◽  
Three Dimensional ◽  
Angular Separation ◽  
Broadband Noise ◽  
Auditory Display ◽  
Signal To Noise ◽  
Correlated Sources ◽  
Auditory Displays

The extent to which simultaneous inputs in a three-dimensional (3D) auditory display mask one another was studied in a simulated sonar task. The minimum signal-to-noise ratio (SNR) required to detect an amplitude-modulated SOO-Hz tone in a background of broadband noise was measured using a loudspeaker array in a free field. Three aspects of the 3D array were varied: angular separation of the sources, degree of correlation of the background noises, and listener head movement. Masking was substantially reduced when the sources were uncorrelated. The SNR needed for detection decreased with source separation, and the rate of decrease was significantly greater with uncorrelated sources than with partially or fully correlated sources. Head movement had no effect on the SNR required for detection. Implications for the design and application of 3D auditory displays are discussed.

Headphone Localization of Speech

1993 ◽  
Vol 35 (2) ◽  
pp. 361-376 ◽  
Author(s):  
Durand R. Begault ◽  
Elizabeth M. Wenzel
Keyword(s):  
Transfer Functions ◽  
Three Dimensional ◽  
Median Plane ◽  
Spatial Location ◽  
Broadband Noise ◽  
Sound Sources ◽  
Speech Stimuli ◽  
Spectral Changes ◽  
Distance Judgments ◽  
Display Systems

Three-dimensional acoustic display systems have recently been developed that synthesize virtual sound sources over headphones based on filtering by headrelated transfer functions (HRTFs), the direction-dependent spectral changes caused primarily by the pinnae. In this study 11 inexperienced subjects judged the apparent spatial location of headphone-presented speech stimuli filtered with nonindividualized HRTFs. About half of the subjects "pulled" their judgments toward either the median or the lateral-vertical planes, and estimates were almost always elevated. Individual differences were pronounced for the distance judgments; 15% to 46% of stimuli were heard inside the head, with the shortest estimates near the median plane. The results suggest that most listeners can obtain useful azimuth information from speech stimuli filtered by nonindividualized HRTFs. Measurements of localization error and reversal rates are comparable with a previous study that used broadband noise stimuli.

Segregation of Multiple Talkers in the Vertical Plane: Implications for the Design of a Multiple Talker Display

2002 ◽  
Vol 46 (4) ◽  
pp. 588-591 ◽  
Author(s):  
Ken I. McAnally ◽  
Robert S. Bolia ◽  
Russell L Martin ◽  
Geoff Eberle ◽  
Douglas S. Brungart
Keyword(s):  
Speech Intelligibility ◽  
Vertical Plane ◽  
Spatial Separation ◽  
Median Plane ◽  
Spatial Audio ◽  
Interaural Time Differences ◽  
The Third ◽  
Release From Masking

Three experiments were conducted to evaluate the effect of spatial separation of multiple talkers in the vertical plane on speech intelligibility. The first experiment demonstrated a release from masking due to separation in the median plane, and that this release was not due to the presence of residual interaural time differences (ITDs). The second experiment showed that this release corresponded to an increase in signal level of 1.3 dB. The third experiment demonstrated that the increase in intelligibility due to separation in elevation and that due to separation in azimuth were not additive. Results are discussed in terms of their implications for the design of spatial audio displays.

The Effect of Nonlinear Amplitude Growth on the Speech Perception Benefits Provided by a Single-Sided Vocoder

2019 ◽  
Vol 62 (3) ◽  
pp. 745-757 ◽  
Author(s):  
Jessica M. Wess ◽  
Joshua G. W. Bernstein
Keyword(s):  
Transfer Functions ◽  
Spatial Configuration ◽  
Free Field ◽  
Spatial Separation ◽  
Compression And Expansion ◽  
Interaural Difference ◽  
Interaural Differences ◽  
Single Sided Deafness ◽  
Perceptual Separation ◽  
Loudness Growth

PurposeFor listeners with single-sided deafness, a cochlear implant (CI) can improve speech understanding by giving the listener access to the ear with the better target-to-masker ratio (TMR; head shadow) or by providing interaural difference cues to facilitate the perceptual separation of concurrent talkers (squelch). CI simulations presented to listeners with normal hearing examined how these benefits could be affected by interaural differences in loudness growth in a speech-on-speech masking task.MethodExperiment 1 examined a target–masker spatial configuration where the vocoded ear had a poorer TMR than the nonvocoded ear. Experiment 2 examined the reverse configuration. Generic head-related transfer functions simulated free-field listening. Compression or expansion was applied independently to each vocoder channel (power-law exponents: 0.25, 0.5, 1, 1.5, or 2).ResultsCompression reduced the benefit provided by the vocoder ear in both experiments. There was some evidence that expansion increased squelch in Experiment 1 but reduced the benefit in Experiment 2 where the vocoder ear provided a combination of head-shadow and squelch benefits.ConclusionsThe effects of compression and expansion are interpreted in terms of envelope distortion and changes in the vocoded-ear TMR (for head shadow) or changes in perceived target–masker spatial separation (for squelch). The compression parameter is a candidate for clinical optimization to improve single-sided deafness CI outcomes.

Effects of target level on release from masking by voice-gender difference and spatial separation between talkers

2021 ◽  
Vol 150 (4) ◽  
pp. A304-A304
Author(s):  
Yonghee Oh ◽  
Hannah Schoenfeld ◽  
Allison O. Layne ◽  
Sarah E. Bridges
Keyword(s):  
Gender Difference ◽  
Spatial Separation ◽  
Target Level ◽  
Release From Masking

scholarly journals ESTRUCTURA DE LA COMUNIDAD EPIFAUNAL ASOCIADA A COLONIAS DE VIDA LIBRE DEL HIDROCORAL MILLEPORA ALCICORNIS LINNAEUS 1758 EN BAHÍA PORTETE, CARIBE COLOMBIANO

2016 ◽  
Vol 35 ◽  
Author(s):  
Carolina Castro S. ◽  
Mario Monroy L. ◽  
Oscar David Solano
Keyword(s):  
Coral Species ◽  
Three Dimensional ◽  
Spatial Separation ◽  
Juvenile Stage ◽  
Living Tissue ◽  
Free Living ◽  
Invertebrate Species ◽  
Epifaunal Community ◽  
Dimensional Growth ◽  
Petrolisthes Armatus

The epifaunal community associated with free-living colonies of Millepora alcicornis, the dominant coral species in Portete Bay, was characterized from twenty living colonies randomly collected within a shallow Thalassia testudinum seabed. The three-dimensional growth colonies sheltered 15 families, 15 genera and 18 mobile invertebrate species. The 97% of individuals was represented by decapods crustaceans specially adapted as to live in association with the host. Within them, the porcelanid Petrolisthes armatus, representing 79% of the epifauna (961 individuals), was exclusively found in a juvenile stage suggesting that M. alcicornis is mainly used by this species as a nursery zone. The epifaunal composition is partially related to coral living tissue whereas the principal simbionts size is correlated with the spatial separation of coral branches. In spite of being slightly diverse in comparison with the epifaunal community found in other coral species, the epifauna found in M. alcicornis is of great interest and peculiarity by their association with the free-living form of this coral.

scholarly journals Contribution of bone-reverberated waves to sound localization of dolphins: A numerical model

Acta Acustica ◽  
2020 ◽  
Vol 5 ◽  
pp. 3
Author(s):  
Aida Hejazi Nooghabi ◽  
Quentin Grimal ◽  
Anthony Herrel ◽  
Michael Reinwald ◽  
Lapo Boschi
Keyword(s):  
Wave Propagation ◽  
Numerical Model ◽  
Sound Localization ◽  
Three Dimensional ◽  
Vertical Plane ◽  
Dimensional Structure ◽  
Bone Modeling ◽  
Sound Sources ◽  
Localization Accuracy ◽  
Future Work

We implement a new algorithm to model acoustic wave propagation through and around a dolphin skull, using the k-Wave software package [1]. The equation of motion is integrated numerically in a complex three-dimensional structure via a pseudospectral scheme which, importantly, accounts for lateral heterogeneities in the mechanical properties of bone. Modeling wave propagation in the skull of dolphins contributes to our understanding of how their sound localization and echolocation mechanisms work. Dolphins are known to be highly effective at localizing sound sources; in particular, they have been shown to be equally sensitive to changes in the elevation and azimuth of the sound source, while other studied species, e.g. humans, are much more sensitive to the latter than to the former. A laboratory experiment conducted by our team on a dry skull [2] has shown that sound reverberated in bones could possibly play an important role in enhancing localization accuracy, and it has been speculated that the dolphin sound localization system could somehow rely on the analysis of this information. We employ our new numerical model to simulate the response of the same skull used by [2] to sound sources at a wide and dense set of locations on the vertical plane. This work is the first step towards the implementation of a new tool for modeling source (echo)location in dolphins; in future work, this will allow us to effectively explore a wide variety of emitted signals and anatomical features.

scholarly journals Competitive and Recreational Running Kinematics Examined Using Principal Components Analysis

Healthcare ◽  
2021 ◽  
Vol 9 (10) ◽  
pp. 1321
Author(s):  
Wenjing Quan ◽  
Huiyu Zhou ◽  
Datao Xu ◽  
Shudong Li ◽  
Julien S. Baker ◽  
...  
Keyword(s):  
Principal Component Analysis ◽  
Principal Components ◽  
Sagittal Plane ◽  
Three Dimensional ◽  
Frontal Plane ◽  
Principal Component ◽  
Component Analysis ◽  
Ankle Inversion ◽  
Motion System ◽  
Recreational Runners

Kinematics data are primary biomechanical parameters. A principal component analysis (PCA) of waveforms is a statistical approach used to explore patterns of variability in biomechanical curve datasets. Differences in experienced and recreational runners’ kinematic variables are still unclear. The purpose of the present study was to compare any differences in kinematics parameters for competitive runners and recreational runners using principal component analysis in the sagittal plane, frontal plane and transverse plane. Forty male runners were divided into two groups: twenty competitive runners and twenty recreational runners. A Vicon Motion System (Vicon Metrics Ltd., Oxford, UK) captured three-dimensional kinematics data during running at 3.3 m/s. The principal component analysis was used to determine the dominating variation in this model. Then, the principal component scores retained the first three principal components and were analyzed using independent t-tests. The recreational runners were found to have a smaller dorsiflexion angle, initial dorsiflexion contact angle, ankle inversion, knee adduction, range motion in the frontal knee plane and hip frontal plane. The running kinematics data were influenced by running experience. The findings from the study provide a better understanding of the kinematics variables for competitive and recreational runners. Thus, these findings might have implications for reducing running injury and improving running performance.

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