Toward a Unified Theory of the Reference Frame of the Ventriloquism Aftereffect

This article was published in Trends in hearing: Sage journal.This work was supported by the Slovak Scientific Grant Agency VEGA (Grant no. 1/0350/22) and EU Danube Region Strategy grant ASH (Grant Nos. APVV DS-FR-19-0025, WTZ MULT 07/2020, 45268RE)

Nonnative implicit phonetic training in multiple reverberant environments.

Speech intelligibility is adversely affected by reverberation, particularly when listening to a foreign language. However, little is known about how phonetic learning is affected by room acoustics. This study investigated how room reverberation impacts the acquisition of novel phonetic categories during implicit training in virtual environments. Listeners were trained to distinguish a difficult nonnative dental-retroflex contrast in phonemes presented either in a fixed room (anechoic or reverberant) or in multiple anechoic and reverberant spaces typical of everyday listening. Training employed a videogame in which phonetic stimuli were paired with rewards delivered upon successful task performance, in accordance with the task-irrelevant perceptual learning paradigm. Before and after training, participants were tested using familiar and unfamiliar speech tokens, speakers, and rooms. Implicit training performed in multiple rooms induced learning, while training in a single environment did not. The multiple-room training improvement generalized to untrained rooms and tokens, but not to untrained voices. These results show that, following implicit training, nonnative listeners can overcome the detrimental effects of reverberation and that exposure to sounds in multiple reverberant environments during training enhances implicit phonetic learning rather than disrupting it

Auditory-visual interactions in egocentric distance perception: Ventriloquism effect and aftereffect

This article was published in The Journal of the Acoustical Society of America, 2021

Effects of cuing on perceived location of auditory sources

Introduction One of the goals of computational intelligence is to determine how biological systems solve difficult problems in order to apply these approaches to technical applications. The way in which biological systems compute sound source location from the acoustic signals reaching the ears can be instructive in this way, because biological systems do a remarkably good job of determining sound locations from what are often ambiguous, noisy acoustic spatial cues. Figure 1 shows a diagram that outlines the neural pathway involved in the computation of the sound source position. As shown in Figure 1, the neural pathway for extracting source location is very hierarchical, involving many stages of processing even before the level of the cortex. Basic spatial cues are first extracted in the brainstem before being integrated in the midbrain. The resulting signals then reach the cortex, which governs high-level spatial behaviors. In addition to the feed-forward paths shown in Figure 1 (

Nonnative implicit phonetic training in multiple reverberant environments.

Speech intelligibility is adversely affected by reverberation, particularly when listening to a foreign language. However, little is known about how phonetic learning is affected by room acoustics. This study investigated how room reverberation impacts the acquisition of novel phonetic categories during implicit training in virtual environments. Listeners were trained to distinguish a difficult nonnative dental-retroflex contrast in phonemes presented either in a fixed room (anechoic or reverberant) or in multiple anechoic and reverberant spaces typical of everyday listening. Training employed a videogame in which phonetic stimuli were paired with rewards delivered upon successful task performance, in accordance with the task-irrelevant perceptual learning paradigm. Before and after training, participants were tested using familiar and unfamiliar speech tokens, speakers, and rooms. Implicit training performed in multiple rooms induced learning, while training in a single environment did not. The multiple-room training improvement generalized to untrained rooms and tokens, but not to untrained voices. These results show that, following implicit training, nonnative listeners can overcome the detrimental effects of reverberation and that exposure to sounds in multiple reverberant environments during training enhances implicit phonetic learning rather than disrupting it

PointMap: A real-time memory-based learning system with on-line and post-training pruning

Abstract. A memory-based learning system called PointMap is a simple and computationally efficient extension of Condensed Nearest Neighbor that allows the user to limit the number of exemplars stored during incremental learning. PointMap evaluates the information value of coding nodes during training, and uses this index to prune uninformative nodes either on-line or after training. These pruning methods allow the user to control both a priori code size and sensitivity to detail in the training data, as well as to determine the code size necessary for accurate performance on a given data set. Coding and pruning computations are local in space, with only the nearest coded neighbor available for comparison with the input; and in time, with only the current input available during coding. Pruning helps solve common problems of traditional memory-based learning systems: large memory requirements, their accompanying slow on-line computations, and sensitivity to noise. PointMap copes with the curse of dimensionality by considering multiple nearest neighbors during testing without increasing the complexity of the training process or the stored code. The performance of PointMap is compared to that of a group of sixteen nearest-neighbor systems on benchmark problems

Calibration of speech perception to room reverberation

Past studies of sound perception often assumed that our auditory sensory processes are relatively static, rather than plastic. However, in everyday environments, we naturally and fluidly compensate for interfering effects of background noise and room reverberation. In order to investigate how listeners calibrate auditory perception to such acoustic interference, a listening experiment was performed to measure the effect of sudden changes of reverberation on the identification of consonants. Binaural room impulse responses (BRIRs) measured in real rooms were convolved with speech tokens to simulate natural interference caused by reverberant energy. In the experiment, listeners identified the consonant present in a vowel-consonant target. On most trials, the target was presented following a carrier phrase (in a control condition, there was no preceding carrier). In some cases, the target and carrier phrase were processed by the same BRIRs while in others the BRIRs processing target and carrier differed in their types of reverberation. Results suggest that presenting a carrier and target with matching BRIRs improves accuracy of target consonant identification compared to cases in which the reverberation of the preceding carrier does not match that of the target.

Auditory Localization in Rooms: Acoustic Analysis and Behavior

In an ordinary room, reverberation and echoes in the signals reaching a listener’s ears influence auditory localization performance. The energy of the echoes and reverberation depends on the position of the listener in the room as well as on the position of the sound source relative to the listener. In this paper, the effects of echoes and reverberation are quantified through analysis of reverberant Head-Related Transfer Functions (HRTFs) measured in an ordinary classroom. HRTFs were measured for several human listeners and a KEMAR acoustic manikin at four different listener positions in the room and multiple source positions relative to the listener. Azimuthal localization performance was also measured for several listeners in the room as a function of listener position. Compared to the acoustic cues it was found to be less sensitive to a change in room location. The only similarity was found between the magnitude of frequency-to-frequency variations in basic localization cues and the variability in localization performance, demonstrating that localization accuracy decreases with increasing reverberant energy

Learning to judge distance of nearby sounds in reverberant and anechoic environments

Some recent studies of auditory distance perception in rea