%0 Journal Article
%~ PubMed
%A Allen, Kachina
%A Alais, David
%A Carlile, Simon
%T A Collection of Pseudo-Words to Study Multi-Talker Speech Intelligibility without Shifts of Spatial Attention.
%B Frontiers in Psychology
%D 2012
%C Switzerland
%I Frontiers Research Foundation
%V 3
%N 
%P 49
%@ 1664-1078
%X 
%Z FOR Codes: 170112


%0 Book Section
%A Best, Virginia
%A Brungart, Douglas
%A Carlile, Simon
%A Jin, C
%A Macpherson, E.A.
%A Martin, R.L.
%A McAnally, K.I.
%A Sabin, A.T.
%A Simpson, B.D.
%T A Meta-analysis of localization errors made in the anechoic free field
%B Principles and Applications of Spatial Hearing
%D 2011
%C Singapore
%I World Scientific Publishing
%V 
%N 
%P 14-23
%@ 9789814313872
%E Suzuki, Yoiti
%E Brungart, Doublas
%E Iwaya, Yukio
%E Lida, Kazuhiro
%E Cabrera, Densil
%E Kato, Hiroaki
%X 
%Z FOR Codes: 110315 1109


%0 Journal Article
%~ PubMed
%A Best, Virginia
%A Carlile, Simon
%A Kopco, Norbert
%A van Schaik, Andre??
%T Localization in speech mixtures by listeners with hearing loss.
%B The Journal of the Acoustical Society of America
%D 2011
%C United States
%I Acoustical Society of America
%V 129
%N 5
%P EL210
%@ 1520-8524
%X The ability of listeners with bilateral sensorineural hearing loss to localize a speech source in a multitalker mixture was measured. Five simultaneous words spoken by different talkers were presented over loudspeakers in a small room, and listeners localized one target word. Errors were significantly larger in this group compared to a control group with normal hearing. Localization of the target presented alone was not different between groups. The results suggest that hearing loss does not impair spatial hearing per se, but degrades the spatial representation of multiple simultaneous sounds.
%Z FOR Codes: 110906


%0 Journal Article
%~ PubMed
%A Allen, Kachina
%A Alais, David
%A Shinn-Cunningham, Barbara
%A Carlile, Simon
%T Masker location uncertainty reveals evidence for suppression of maskers in two-talker contexts.
%B The Journal of the Acoustical Society of America
%D 2011
%C United States
%I Acoustical Society of America
%V 130
%N 4
%P 2043
%@ 1520-8524
%X In many natural settings, spatial release from masking aids speech intelligibility, especially when there are competing talkers. This paper describes a series of three experiments that investigate the role of prior knowledge of masker location on phoneme identification and spatial release from masking. In contrast to previous work, these experiments use initial stop-consonant identification as a test of target intelligibility to ensure that listeners had little time to switch the focus of spatial attention during the task. The first experiment shows that target phoneme identification was worse when a masker played from an unexpected location (increasing the consonant identification threshold by 2.6 dB) compared to when an energetically very similar and symmetrically located masker came from an expected location. In the second and third experiments, target phoneme identification was worse (increasing target threshold levels by 2.0 and 2.6 dB, respectively) when the target was played unexpectedly on the side from which the masker was expected compared to when the target came from an unexpected, symmetrical location in the hemifield opposite the expected location of the masker. These results support the idea that listeners modulate spatial attention by both focusing resources on the expected target location and withdrawing attentional resources from expected locations of interfering sources.
%Z FOR Codes: 110906


%0 Book Section
%A Carlile, Simon
%T Psychoacoustics
%B The Sonification Handbook
%D 2011
%C Germany
%I Logos Verlag Berlin GmbH
%V 
%N 
%P 41-61
%@ 9783832528195
%E Hermann, Thomas
%E Hunt, Andy
%E Neuhoff, John G.
%X 
%Z FOR Codes: 110906


%0 Journal Article
%~ PubMed
%A Best, Virginia
%A Kalluri, Sridhar
%A McLachlan, Sara
%A Valentine, Susie
%A Edwards, Brent
%A Carlile, Simon
%T A comparison of CIC and BTE hearing aids for three-dimensional localization of speech.
%B International journal of audiology
%D 2010
%C United Kingdom, Norw
%I Informa Healthcare
%V 49
%N 
%P 723-32
%@ 1708-8186
%X Three-dimensional sound localization of speech in anechoic space was examined for eleven listeners with sensorineural hearing loss. The listeners were fitted bilaterally with CIC and BTE hearing aids having similar bandwidth capabilities. The goal was to determine whether differences in microphone placement for these two styles (CICs at the ear canal entrance; BTEs above the pinna) would influence the availability of pinna-related spectral cues and hence localization performance. While lateral and polar angle localization was unaffected by the hearing aid style, the rate of front-back reversals was lower with CICs. This pattern persisted after listeners accommodated to each set of aids for a six week period, although the overall rate of reversals declined. Performance on all measures in all conditions was considerably poorer than in a control group of listeners with normal hearing.
%Z FOR Codes: 110906 170112


%0 Journal Article
%A Hartmann, William M
%A Best, Virginia
%A Leung, Johahn
%A Carlile, Simon
%T Phase effects on the perceived elevation of complex tones
%B The Journal of the Acoustical Society of America
%D 2010
%C United States
%I Acoustical Society of America
%V 127
%N 5
%P 3060-3072
%@ 0001-4966
%X 
%Z FOR Codes: 110315


%0 Journal Article
%~ PubMed
%A Kopco, Norbert
%A Best, Virginia
%A Carlile, Simon
%T Speech localization in a multitalker mixture.
%B The Journal of the Acoustical Society of America
%D 2010
%C United States
%I Acoustical Society of America
%V 127
%N 3
%P 1450-1457
%@ 1520-8524
%X An experiment was performed that measured, for the frontal audio-visual horizon, how accurately listeners could localize a female-voice target amidst four spatially distributed male-voice maskers. To examine whether listeners can make use of a priori knowledge about the configuration of the sources, performance was examined in two conditions: either the masker locations were fixed (in one of five known patterns) or the locations varied from trial to trial. The presence of maskers disrupted speech localization, even after accounting for reduced target detectability. Averaged across all target locations, the rms error in responses decreased by 20% when a priori knowledge about masker locations was available. The effect was even stronger for the target locations that did not coincide with the maskers (error reduction of 36%), while no change in errors was observed for targets coinciding with maskers. The benefits were reduced when the target-to-masker intensity ratio was increased or when the maskers were in a pattern that made it difficult to make use of the a priori information. The results confirm that localization in speech mixtures is modified by the listener''s expectations about the spatial arrangement of the sources.
%Z FOR Codes: 170112


%0 Journal Article
%~ PubMed
%A Neher, Tobias
%A Behrens, Thomas
%A Carlile, Simon
%A Jin, Craig
%A Kragelund, Louise
%A Petersen, Anne Specht
%A Schaik, André van
%T Benefit from spatial separation of multiple talkers in bilateral hearing-aid users: Effects of hearing loss, age, and cognition.
%B International Journal of Audiology
%D 2009
%C United Kingdom, Norw
%I Informa Healthcare
%V 48
%N 11
%P 758-774
%@ 1708-8186
%X To study the spatial hearing abilities of bilateral hearing-aid users in multi-talker situations, 20 subjects received fittings configured to preserve acoustic cues salient for spatial hearing. Following acclimatization, speech reception thresholds (SRTs) were measured for three competing talkers that were either co-located or spatially separated along the front-back or left-right dimension. In addition, the subjects'' working memory and attentional abilities were measured. Left-right SRTs varied over more than 14 dB, while front-back SRTs varied over more than 8 dB. Furthermore, significant correlations were observed between left-right SRTs, age, and low-frequency hearing loss, and also between front-back SRTs, age, and high-frequency aided thresholds. Concerning cognitive effects, left-right performance was most strongly related to attentional abilities, while front-back performance showed a relation to working memory abilities. Altogether, these results suggest that, due to raised hearing thresholds and aging, hearing-aid users have reduced access to interaural and monaural spatial cues as well as a diminished ability to ''enhance'' a target signal by means of top-down processing. These deficits, in turn, lead to impaired functioning in complex listening environments.
%Z FOR Codes: 110399


%0 Journal Article
%~ PubMed
%A Allen, Kachina
%A Alais, David
%A Carlile, Simon
%T Speech intelligibility reduces over distance from an attended location: evidence for an auditory spatial gradient of attention.
%B Attention, Perception & Psychophysics
%D 2009
%C United States
%I Psychonomic Society, Inc.
%V 71
%N 1
%P 164-173
%@ 1943-3921
%X Speech reception thresholds (SRTs) were measured at a central focus of attention and at 20 degrees, 40 degrees, and 60 degrees locations distant in azimuth. Measurements were taken with one target collocated with two maskers, or with maskers flanking the target by +/-20 degrees. For 80% of trials, the target was played from the attended location ("expected"), and 20% came from another ("unexpected") location. For collocated stimuli, SRTs worsened with increasing distance from the expected location by 2.1 dB over the 60 degrees azimuth and by 5.1 dB for spatially separated target and maskers. In spatially separated conditions, a 2.9-dB change was still found when gaze was away from the attended location. Spatial attention appears to increase speech intelligibility against interferers, with gain decreasing with distance from the focus of attention. Spatial release from masking (RFM) was only found for the attended location. Further experiments suggest that target location uncertainty prevented RFM at unattended locations.
%Z FOR Codes: 110906


%0 Journal Article
%~ PubMed
%A Leung, Johahn
%A Alais, David
%A Carlile, Simon
%T Compression of auditory space during rapid head turns.
%B Proceedings of the National Academy of Sciences
%D 2008
%C United States
%I National Academy of Sciences
%V 105
%N 17
%P 6492-6497
%@ 0027-8424
%X Studies of spatial perception during visual saccades have demonstrated compressions of visual space around the saccade target. Here we psychophysically investigated perception of auditory space during rapid head turns, focusing on the "perisaccadic" interval. Using separate perceptual and behavioral response measures we show that spatial compression also occurs for rapid head movements, with the auditory spatial representation compressing by up to 50%. Similar to observations in the visual system, this occurred only when spatial locations were measured by using a perceptual response; it was absent for the behavioral measure involving a nose-pointing task. These findings parallel those observed in vision during saccades and suggest that a common neural mechanism may subserve these distortions of space in each modality.
%Z FOR Codes: 110906


%0 Journal Article
%~ PubMed
%A Allen, Kachina
%A Carlile, Simon
%A Alais, David
%T Contributions of talker characteristics and spatial location to auditory streaming.
%B The Journal of the Acoustical Society of America
%D 2008
%C United States
%I Acoustical Society of America
%V 123
%N 3
%P 1562-1570
%@ 1520-8524
%X To examine whether auditory streaming contributes to unmasking, intelligibility of target sentences against two competing talkers was measured using the coordinate response measure (CRM) [Bolia et al., J. Acoust. Soc. Am. 107, 1065-1066 (2007)] corpus. In the control condition, the speech reception threshold (50% correct) was measured when the target and two maskers were collocated straight ahead. Separating maskers from the target by +/-30 degrees resulted in spatial release from masking of 12 dB. CRM sentences involve an identifier in the first part and two target words in the second part. In experimental conditions, masking talkers started spatially separated at +/-30 degrees but became collocated with the target before the scoring words. In one experiment, one target and two different maskers were randomly selected from a mixed-sex corpus. Significant unmasking of 4 dB remained despite the absence of persistent location cues. When same-sex talkers were used as maskers and target, unmasking was reduced. These data suggest that initial separation may permit confident identification and streaming of the target and masker speech where significant differences between target and masker voice characteristics exist, but where target and masker characteristics are similar, listeners must rely more heavily on continuing spatial cues.
%Z FOR Codes: 110906


%0 Journal Article
%~ PubMed
%A Cooper, Joel
%A Carlile, Simon
%A Alais, David
%T Distortions of auditory space during rapid head turns.
%B Exp Brain Res
%D 2008
%C Germany
%I Springer
%V 191
%N 2
%P 209-19
%@ 1432-1106
%X Auditory localisation was examined using brief broadband sounds presented during rapid head turns to visual targets in the peripheral field. Presenting sounds during a rapid head movement will "smear" the acoustic cues to the sound''s location. During the early stages of a head turn, sound localisation accuracy was comparable to a no-turn control condition. However, significant localisation errors occurred when the probe sound was presented during the later part of a head turn. After correcting for head position, the estimate of lateral angle (horizontal position) in the front hemisphere was generally accurate. However, lateral angle estimates for positions in the rear hemisphere exhibited systematic errors that were especially large around the midline. Polar angle (elevation) perception remained robust, being comparable to no-turn controls whether tested early or late in the head turn. The results are interpreted in terms of a ''multiple look'' strategy for calculating sound location, and the allocation of attention to the hemisphere containing the head-turn target.
%Z FOR Codes: 110906


%0 Journal Article
%~ PubMed
%A Campbell, Robert A A
%A King, Andrew J
%A Nodal, Fernando R
%A Schnupp, Jan W H
%A Carlile, Simon
%A Doubell, Timothy P
%T Virtual adult ears reveal the roles of acoustical factors and experience in auditory space map development.
%B The Journal of neuroscience
%D 2008
%C United States
%I Society for Neuroscience
%V 28
%N 45
%P 11557-70
%@ 1529-2401
%X Auditory neurons in the superior colliculus (SC) respond preferentially to sounds from restricted directions to form a map of auditory space. The development of this representation is shaped by sensory experience, but little is known about the relative contribution of peripheral and central factors to the emergence of adult responses. By recording from the SC of anesthetized ferrets at different age points, we show that the map matures gradually after birth; the spatial receptive fields (SRFs) become more sharply tuned and topographic order emerges by the end of the second postnatal month. Principal components analysis of the head-related transfer function revealed that the time course of map development is mirrored by the maturation of the spatial cues generated by the growing head and external ears. However, using virtual acoustic space stimuli, we show that these acoustical changes are not by themselves responsible for the emergence of SC map topography. Presenting stimuli to infant ferrets through virtual adult ears did not improve the order in the representation of sound azimuth in the SC. But by using linear discriminant analysis to compare different response properties across age, we found that the SRFs of infant neurons nevertheless became more adult-like when stimuli were delivered through virtual adult ears. Hence, although the emergence of auditory topography is likely to depend on refinements in neural circuitry, maturation of the structure of the SRFs (particularly their spatial extent) can be largely accounted for by changes in the acoustics associated with growth of the head and ears.
%Z FOR Codes: 110999


%0 Journal Article
%~ Isi
%A Shinn-Cunningham, BG
%A Best, V
%A Gallun, FJ
%A Carlile, S
%T Binaural interference and auditory grouping
%B JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA
%D 2007
%C United States
%I Acoustical Society of America
%V 121
%N 2
%P 1070-1076
%@ 0001-4966
%X 
%Z FOR Codes: 110906


%0 Journal Article
%A Carlile, Simon
%T Listening to the world around us
%B Acoustics Australia
%D 2006
%C Australia
%I Australian Acoustical Society
%V 34
%N 
%P 5-11
%@ 0814-6039
%X 
%Z FOR Codes: 110399