scholarly journals The role of spectral composition of sounds on the localization of sound sources by cats

2013 ◽  
Vol 109 (6) ◽  
pp. 1658-1668 ◽  
Author(s):  
Daniel J. Tollin ◽  
Janet L. Ruhland ◽  
Tom C. T. Yin
Keyword(s):  
Sound Localization ◽  
Spectral Composition ◽  
Power Spectra ◽  
Sound Sources ◽  
Gaze Shift ◽  
Localization Accuracy ◽  
Low Pass ◽  
Localization Performance ◽  
High Pass

Sound localization along the azimuthal dimension depends on interaural time and level disparities, whereas localization in elevation depends on broadband power spectra resulting from the filtering properties of the head and pinnae. We trained cats with their heads unrestrained, using operant conditioning to indicate the apparent locations of sounds via gaze shift. Targets consisted of broadband (BB), high-pass (HP), or low-pass (LP) noise, tones from 0.5 to 14 kHz, and 1/6 octave narrow-band (NB) noise with center frequencies ranging from 6 to 16 kHz. For each sound type, localization performance was summarized by the slope of the regression relating actual gaze shift to desired gaze shift. Overall localization accuracy for BB noise was comparable in azimuth and in elevation but was markedly better in azimuth than in elevation for sounds with limited spectra. Gaze shifts to targets in azimuth were most accurate to BB, less accurate for HP, LP, and NB sounds, and considerably less accurate for tones. In elevation, cats were most accurate in localizing BB, somewhat less accurate to HP, and less yet to LP noise (although still with slopes ∼0.60), but they localized NB noise much worse and were unable to localize tones. Deterioration of localization as bandwidth narrows is consistent with the hypothesis that spectral information is critical for sound localization in elevation. For NB noise or tones in elevation, unlike humans, most cats did not have unique responses at different frequencies, and some appeared to respond with a “default” location at all frequencies.

scholarly journals Changes in Sound Localization Performance of Single-Sided Deaf Listeners after Visual Feedback Training in Azimuth

2020 ◽  
Author(s):  
Bahram Zonooz ◽  
A. John Van Opstal
Keyword(s):  
Visual Feedback ◽  
Horizontal Plane ◽  
Directional Hearing ◽  
Sound Sources ◽  
Feedback Training ◽  
Spectral Cues ◽  
Low Pass ◽  
Localization Performance ◽  
Multisensory Information ◽  
High Pass

AbstractChronic single-sided deaf (CSSD) listeners lack the availability of binaural difference cues to localize sounds in the horizontal plane. Hence, for directional hearing they have to rely on different types of monaural cues: loudness perceived in their hearing ear, which is affected in a systematic way by the acoustic head shadow, on spectral cues provided by the low-pass filtering characteristic of the head, and on high-frequency spectral-shape cues from the pinna of their hearing ear. Presumably, these cues are differentially weighted against prior assumptions on the properties of sound sources in the environment. The rules guiding this weighting process are not well understood. In this preliminary study, we trained three CSSD listeners to localize a fixed intensity, high-pass filtered sound source at ten locations in the horizontal plane with visual feedback. After training, we compared their localization performance to sounds with different intensities, presented in the two-dimensional frontal hemifield to their pre-training results. We show that the training had rapidly readjusted the contributions of monaural cues and internal priors, which resulted to be imposed by the multisensory information provided during the training. We compare the results with the strategies found for the acute monaural hearing condition of normal-hearing listeners, described in an earlier study [1].

Role of pinnae and head movements in localizing pure tones 1The authors would like to thank Mr. Remi Humbert for implementing the experiment in Turbo Pascal and for his further assistance.

1999 ◽  
Vol 58 (3) ◽  
pp. 170-179 ◽  
Author(s):  
Barbara S. Muller ◽  
Pierre Bovet
Keyword(s):  
Sound Source ◽  
Head Movement ◽  
Movement Analysis ◽  
Head Movements ◽  
Sound Sources ◽  
Localization Accuracy ◽  
Sound Effects ◽  
Posterior Quadrant ◽  
Localization Performance ◽  
Pure Tones

Twelve blindfolded subjects localized two different pure tones, randomly played by eight sound sources in the horizontal plane. Either subjects could get information supplied by their pinnae (external ear) and their head movements or not. We found that pinnae, as well as head movements, had a marked influence on auditory localization performance with this type of sound. Effects of pinnae and head movements seemed to be additive; the absence of one or the other factor provoked the same loss of localization accuracy and even much the same error pattern. Head movement analysis showed that subjects turn their face towards the emitting sound source, except for sources exactly in the front or exactly in the rear, which are identified by turning the head to both sides. The head movement amplitude increased smoothly as the sound source moved from the anterior to the posterior quadrant.

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 The role of envelope shape in the localization of multiple sound sources and echoes in the barn owl

2013 ◽  
Vol 109 (4) ◽  
pp. 924-931 ◽  
Author(s):  
Caitlin S. Baxter ◽  
Brian S. Nelson ◽  
Terry T. Takahashi
Keyword(s):  
Sound Localization ◽  
Precedence Effect ◽  
Tyto Alba ◽  
Topographic Map ◽  
Sound Sources ◽  
Auditory Space ◽  
Amplitude Spectra ◽  
Barn Owls ◽  
The One

Echoes and sounds of independent origin often obscure sounds of interest, but echoes can go undetected under natural listening conditions, a perception called the precedence effect. How does the auditory system distinguish between echoes and independent sources? To investigate, we presented two broadband noises to barn owls ( Tyto alba) while varying the similarity of the sounds' envelopes. The carriers of the noises were identical except for a 2- or 3-ms delay. Their onsets and offsets were also synchronized. In owls, sound localization is guided by neural activity on a topographic map of auditory space. When there are two sources concomitantly emitting sounds with overlapping amplitude spectra, space map neurons discharge when the stimulus in their receptive field is louder than the one outside it and when the averaged amplitudes of both sounds are rising. A model incorporating these features calculated the strengths of the two sources' representations on the map (B. S. Nelson and T. T. Takahashi; Neuron 67: 643–655, 2010). The target localized by the owls could be predicted from the model's output. The model also explained why the echo is not localized at short delays: when envelopes are similar, peaks in the leading sound mask corresponding peaks in the echo, weakening the echo's space map representation. When the envelopes are dissimilar, there are few or no corresponding peaks, and the owl localizes whichever source is predicted by the model to be less masked. Thus the precedence effect in the owl is a by-product of a mechanism for representing multiple sound sources on its map.

scholarly journals Behavioral and modeling studies of sound localization in cats: effects of stimulus level and duration

2013 ◽  
Vol 110 (3) ◽  
pp. 607-620 ◽  
Author(s):  
Yan Gai ◽  
Janet L. Ruhland ◽  
Tom C. T. Yin ◽  
Daniel J. Tollin
Keyword(s):  
Sound Localization ◽  
Stimulus Level ◽  
Sound Level ◽  
Gaze Shift ◽  
Localization Accuracy ◽  
Long Duration ◽  
Spectral Coding ◽  
Sound Duration ◽  
Sound Spectrum ◽  
Level Effect

Sound localization accuracy in elevation can be affected by sound spectrum alteration. Correspondingly, any stimulus manipulation that causes a change in the peripheral representation of the spectrum may degrade localization ability in elevation. The present study examined the influence of sound duration and level on localization performance in cats with the head unrestrained. Two cats were trained using operant conditioning to indicate the apparent location of a sound via gaze shift, which was measured with a search-coil technique. Overall, neither sound level nor duration had a notable effect on localization accuracy in azimuth, except at near-threshold levels. In contrast, localization accuracy in elevation improved as sound duration increased, and sound level also had a large effect on localization in elevation. For short-duration noise, the performance peaked at intermediate levels and deteriorated at low and high levels; for long-duration noise, this “negative level effect” at high levels was not observed. Simulations based on an auditory nerve model were used to explain the above observations and to test several hypotheses. Our results indicated that neither the flatness of sound spectrum (before the sound reaches the inner ear) nor the peripheral adaptation influences spectral coding at the periphery for localization in elevation, whereas neural computation that relies on “multiple looks” of the spectral analysis is critical in explaining the effect of sound duration, but not level. The release of negative level effect observed for long-duration sound could not be explained at the periphery and, therefore, is likely a result of processing at higher centers.

scholarly journals Sound source localization with varying amount of visual information in virtual reality

2018 ◽  
Author(s):  
Axel Ahrens ◽  
Kasper Duemose Lund ◽  
Marton Marschall ◽  
Torsten Dau
Keyword(s):  
Virtual Reality ◽  
Visual Perception ◽  
Sound Localization ◽  
Visual Information ◽  
Right Hemisphere ◽  
Transfer Functions ◽  
Head Movements ◽  
Localization Accuracy ◽  
Localization Performance ◽  
The Right

AbstractTo achieve accurate spatial auditory perception, subjects typically require personal head-related transfer functions (HRTFs) and the freedom for head movements. Loudspeaker-based virtual sound environments allow for realism without individualized measurements. To study audio-visual perception in realistic environments, the combination of spatially tracked head mounted displays (HMDs), also known as virtual reality glasses, and virtual sound environments may be valuable. However, HMDs were recently shown to affect the subjects’ HRTFs and thus might influence sound localization performance. Furthermore, due to limitations of the reproduction of visual information on the HMD, audio-visual perception might be influenced. Here, a sound localization experiment was conducted both with and without an HMD and with a varying amount of visual information provided to the subjects. Furthermore, interaural time and level difference errors (ITDs and ILDs) as well as spectral perturbations induced by the HMD were analyzed and compared to the perceptual localization data. The results showed a reduction of the localization accuracy when the subjects were wearing an HMD and when they were blindfolded. The HMD-induced error in azimuth localization was found to be larger in the left than in the right hemisphere. Thus, the errors in ITD and ILD can only partly account for the perceptual differences. When visual information of the limited set of source locations was provided, the localization error induced by the HMD was found to be negligible. Presenting visual information of hand-location, room dimensions, source locations and pointing feedback on the HMD revealed similar effects as previously shown in real environments.

scholarly journals Sound Source Localization by Hearing Preservation Patients with and without Symmetrical Low-Frequency Acoustic Hearing

2015 ◽  
Vol 20 (3) ◽  
pp. 166-171 ◽  
Author(s):  
Louise H. Loiselle ◽  
Michael F. Dorman ◽  
William A. Yost ◽  
René H. Gifford
Keyword(s):  
Source Localization ◽  
Sound Source ◽  
Low Frequency ◽  
Hearing Preservation ◽  
Sound Source Localization ◽  
Localization Accuracy ◽  
Acoustic Hearing ◽  
Low Pass ◽  
Contralateral Ear ◽  
High Pass

The aim of this article was to study sound source localization by cochlear implant (CI) listeners with low-frequency (LF) acoustic hearing in both the operated ear and in the contralateral ear. Eight CI listeners had symmetrical LF acoustic hearing and 4 had asymmetrical LF acoustic hearing. The effects of two variables were assessed: (i) the symmetry of the LF thresholds in the two ears and (ii) the presence/absence of bilateral acoustic amplification. Stimuli consisted of low-pass, high-pass, and wideband noise bursts presented in the frontal horizontal plane. Localization accuracy was 23° of error for the symmetrical listeners and 76° of error for the asymmetrical listeners. The presence of a unilateral CI used in conjunction with bilateral LF acoustic hearing does not impair sound source localization accuracy, but amplification for acoustic hearing can be detrimental to sound source localization accuracy.

scholarly journals Influence of aging on human sound localization

2011 ◽  
Vol 105 (5) ◽  
pp. 2471-2486 ◽  
Author(s):  
Marina S. Dobreva ◽  
William E. O'Neill ◽  
Gary D. Paige
Keyword(s):  
Sound Localization ◽  
Target Location ◽  
Free Field ◽  
Auditory Target ◽  
Intensity Difference ◽  
Middle Aged ◽  
Auditory Temporal Processing ◽  
Age Related ◽  
Low Pass ◽  
High Pass

Errors in sound localization, associated with age-related changes in peripheral and central auditory function, can pose threats to self and others in a commonly encountered environment such as a busy traffic intersection. This study aimed to quantify the accuracy and precision (repeatability) of free-field human sound localization as a function of advancing age. Head-fixed young, middle-aged, and elderly listeners localized band-passed targets using visually guided manual laser pointing in a darkened room. Targets were presented in the frontal field by a robotically controlled loudspeaker assembly hidden behind a screen. Broadband targets (0.1–20 kHz) activated all auditory spatial channels, whereas low-pass and high-pass targets selectively isolated interaural time and intensity difference cues (ITDs and IIDs) for azimuth and high-frequency spectral cues for elevation. In addition, to assess the upper frequency limit of ITD utilization across age groups more thoroughly, narrowband targets were presented at 250-Hz intervals from 250 Hz up to ∼2 kHz. Young subjects generally showed horizontal overestimation (overshoot) and vertical underestimation (undershoot) of auditory target location, and this effect varied with frequency band. Accuracy and/or precision worsened in older individuals for broadband, high-pass, and low-pass targets, reflective of peripheral but also central auditory aging. In addition, compared with young adults, middle-aged, and elderly listeners showed pronounced horizontal localization deficiencies (imprecision) for narrowband targets within 1,250–1,575 Hz, congruent with age-related central decline in auditory temporal processing. Findings underscore the distinct neural processing of the auditory spatial cues in sound localization and their selective deterioration with advancing age.

scholarly journals Effects of Spatial Frequency Content on Classification of Face Gender and Expression

2010 ◽  
Vol 13 (2) ◽  
pp. 525-537 ◽  
Author(s):  
Luis Aguado ◽  
Ignacio Serrano-Pedraza ◽  
Sonia Rodríguez ◽  
Francisco J. Román
Keyword(s):  
Spatial Frequency ◽  
Reaction Times ◽  
High Spatial Frequency ◽  
Gender Categorization ◽  
Spatial Frequency Filtering ◽  
Low Pass ◽  
Face Experiment ◽  
Expression Classification ◽  
High Pass

The role of different spatial frequency bands on face gender and expression categorization was studied in three experiments. Accuracy and reaction time were measured for unfiltered, low-pass (cut-off frequency of 1 cycle/deg) and high-pass (cut-off frequency of 3 cycles/deg) filtered faces. Filtered and unfiltered faces were equated in root-mean-squared contrast. For low-pass filtered faces reaction times were higher than unfiltered and high-pass filtered faces in both categorization tasks. In the expression task, these results were obtained with expressive faces presented in isolation (Experiment 1) and also with neutral-expressive dynamic sequences where each expressive face was preceded by a briefly presented neutral version of the same face (Experiment 2). For high-pass filtered faces different effects were observed on gender and expression categorization. While both speed and accuracy of gender categorization were reduced comparing to unfiltered faces, the efficiency of expression classification remained similar. Finally, we found no differences between expressive and non expressive faces in the effects of spatial frequency filtering on gender categorization (Experiment 3). These results show a common role of information from the high spatial frequency band in the categorization of face gender and expression.

The Role of High Spatial Frequencies in Face Perception

Perception ◽  
1983 ◽  
Vol 12 (2) ◽  
pp. 195-201 ◽  
Author(s):  
Adriana Fiorentini ◽  
Lamberto Maffei ◽  
Giulio Sandini
Keyword(s):  
Spatial Frequency ◽  
Face Perception ◽  
Energy Content ◽  
High Spatial Frequency ◽  
Face Width ◽  
Spatial Frequencies ◽  
Low Pass ◽  
High Pass ◽  
Spatial Frequency Domain

The relevance of low and high spatial-frequency information for the recognition of photographs of faces has been investigated by testing recognition of faces that have been either low-pass (LP) or high-pass (HP) filtered in the spatial-frequency domain. The highest resolvable spatial frequency was set at 15 cycles per face width (cycles fw−1). Recognition was much less accurate for images that contained only the low spatial frequencies (up to 5 cycles fw−1) than for images that contained only spatial frequencies higher than 5 cycles fw−1. For faces HP filtered above 8 cycles fw−1, recognition was almost as accurate as for faces LP filtered below 8 cycles fw−1, although the energy content of the latter greatly exceeded that of the former. These findings show that information conveyed by the higher spatial frequencies is not redundant. Rather, it is sufficient by itself to ensure recognition.

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