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Report

Teaser, summary, work performed and final results

Periodic Reporting for period 1 - ALT (Adaptation, learning and training for spatial hearing in complex environments)

Teaser

Summary

In everyday listening, humans are exposed to multiple concurrent auditory and speech stimuli in complex, continuously changing environments. To correctly extract relevant information, they adapt their processing to reflect the specifics of the current scene, they learn from previous experience and generalize across new settings. The current project attempts to advance our understanding of the mechanisms that the brain uses to achieve adaptation and learning in complex listening environments.
The main objectives of this research program are to 1) combine behavioral experiments, neural imaging, and computational modeling to study neural adaptation to reverberation for speech processing, sound localization and attentional processing in multi-talker environments, 2) develop a brain training computer game that can enhance the listening capabilities of normal-hearing and hearing-impaired listeners, and 3) organize workshops for students and young researchers to provide them with cognitive neuroscience training related to the consortium research activities.
The main goal of the exchanges performed so far was to develop a program of collaborative research, clinical applications, workshops, and training activities that allows the groups to combine the specific local expertise, special experimental equipment, and technical and methodological expertise available to only one of the groups. Also, the early-stage researchers of the collaborating groups were trained and familiarized with the equipment, methods, and facilities available to only one of the groups, resulting in establishing long-term collaborations among the groups.
A better understanding of the mechanisms underlying adaptation and learning in complex environments will not only advance basic science, but will also help us address better the needs of special populations (e.g., more effective brain training applications for the rehabilitation of people with auditory processing deficits, development of new prosthetic devices and new virtual reality technologies). Furthermore, the workshops, training and exchanges of expertise are resulting in the strengthening of the European Research Area and in the establishment of new long-term collaborations between EU and US researchers.

Work performed

The work performed so far achieved the key objectives of the project is described below, separately for each work package.
WP1: Adaptation to room reverberation for speech perception
An important aspect of real-world speech communication is the ability to adapt to noisy and reverberant listening environments that distort the speech signal and hamper intelligibility. Although even modest levels of reverberation can distort speech, human listeners are able to quickly adapt to the room acoustics and achieve accurate speech communication. This task is harder for nonnative listeners, as interference from room acoustics interacts with their mistuned perception of the sounds from the new language. How the brain manages to adapt to room acoustics to achieve accurate native and nonnative speech perception remains elusive. Our results so far show that 1) phonetic perception quickly adapts to varying environments, but that this adaptation can be fairly different in terms of how accurate the resulting consonant perception is in different environments, and 2) that implicit learning of new phonetic categories can be activated even without explicit feedback, as long as the listener is exposed to the new phonemes in various rooms.
WP2: Sound localization has to adapt to the (anechoic or reverberant) environment in which the stimuli are presented and to the auditory scene if multiple stimuli are presented at the same time. Here, this adaptation processes is examined for auditory distance perception when the acoustic distance cue availability is manipulated and for horizontal perception when complex speech and non-speech stimuli are presented. The main result obtained in this WP is that we show that perceptual organization, i.e., how the brain interprets whether a series of sounds belongs to one source or to multiple sources, can influence our ability to extract spatial information about a sound when it is presented in a context of other distracting sounds â€“ a situation that is very common in everyday listening environments. This result has been published as:
KopÄo, N., AndrejkovÃ¡, G., Best, V. and Shinn-Cunningham, B. (2017). Streaming and sound localization with a preceding distractor. Journal of the Acoustical Society of America, 141, EL331.
WP3: A series of experimental and modelling studies aim to examine auditory processing and calibration of monaural spectral cues in spatial hearing, with focus on externalization of sounds. So far, an experiment was performed that discovered an asymmetry in looming, i.e., in our ability to detect an approaching sound vs. a receding sound, such that the ability to detect an approaching sound is much higher. This result was shown both behaviourally and by the EEG neuroimaging technique. A paper has been published showing this result:
A paper was published summarizing the results: Baumgartner R, DK Reed, B Toth, V Best, P Majdak, HS Colburn, BG Shinn-Cunningham (2017). â€œAsymmetries in behavioral and neural responses to spectral cues demonstrate the generality of looming bias,â€ Proceedings of the National Academy of Sciences, 201703247
WP4 - Auditory brain training game
Here we aim to contribute to the development of novel procedures to rehabilitate auditory processing deficits by developing a brain training game based on modern auditory neuroscience and the results of the current grant. So far, only preparatory activities too place in this WP.
WP5 - Workshops and management
The activities in this WP were in two forms: 1) consortium meetings, usually combined with attendance at conferences, workshops, or other meetings, and 2) Workshop organized by the consortium.
Workshop on â€œCognitive Neuroscience of Auditory and Crossmodal Perceptionâ€ was organized in Kosice from May 29-31, 2017, by the consortium. It was attended by more than 40 students (mostly from Europe) and presenters (from Europe and USA). The ALT-consortium presentations from the workshop are available on the workshop webpage http:

Final results

The main impact of the project is in terms of increased research capacity and improvement of the European Research Area at the EU partners, thanks to transfer of knowledge and expertise from the US partners, and thanks to the world-wide experts participating in the workshops. Specifically, up to date, a lot of new expertise has been obtained in EEG and fMRI neuroimaging methods, and in general in terms of Cognitive Neuroscience knowledge and methodology presented at the Workshops.
The main progress beyond the state of the art is expected in terms of utilizing brain-training games as a new tool for improving perception by normal-hearing and hearing-impaired listeners, as well as a tool in basic auditory neuroscience research. This activity will be the focus during the upcoming period. We are developing brain training applications for populations with special needs, such as war veterans that have been exposed to traumatic brain injuries and experience auditory processing deficits (OSHU) and for normal population for which the aim is to enhance their cognitive and perceptual abilities (UCR Brain Game Center).