10 + 2 PhD / doctoral candidate positions spread over 7 European countries are available in the framework of the Marie Sklodowska-Curie Doctoral Network ‘Cochlear Implants and Spatial Hearing: Enabling access to the next dimension of hearing’ (CherISH).

The loss of inner hair cells in the cochlea causes deafness. To date, cochlear implants are available that can (re-)restore hearing and speech understanding. Yet, so far, the recovery of spatial hearing has been largely neglected, although spatial hearing is central to the control of attention and to enabling speech understanding in noisy environments. Current CIs suffer from technical limitations, and as yet, the availability of effective rehabilitation programs. The interdisciplinary doctoral network, ‘CherISH’ aims at the improvement of spatial hearing in cochlear implant users through a collaborative effort of the three fields: biomedical engineering, medicine, and psychology. In ten different interconnected projects, spatial hearing will be improved by (1) assistive devices facilitating the restoration of spatial hearing by identifying the location of sound sources and providing the information to the CI users through visual or tactile spatial cues, (2) examining physiological impairments of spatial hearing in CI users and matching the imbalance of the binaural inputs, and by (3) patient-centered training programs that make use of virtual spatial sound environments. The doctoral training network will provide the next generation of researchers and engineers with a profound understanding of the multifaceted problems of spatial hearing in hearing impaired individuals. The collaboration between academia and the private sector enables the realization of new solutions for spatial hearing with CIs, thus enabling deaf patients to restore good hearing.

The EU training network will host 10+ 2 Doctoral candidates (DCs) in 7 European countries. The training will be realized in collaboration with 4 associated partners.

The research projects of the 10+2 DCs target the following objectives:

(1) In order to develop optimal therapeutic interventions for the restoration of spatial hearing in cochlear implant users, the manifold causes for impaired SH at different levels of the auditory pathway will be studied using psychophysical, neurophysiological and modelling approaches.

(2) Binaural timings and intensity levels of the pulses stimulating the auditory nerve will be fine-tuned to supply binaural cues of sound localization to CI users.

(3) Novel behavioral training protocols for improving spatial hearing in CI users will be tested:

     (a) Spatial hearing will be trained using a multisensory training in which spatial sound stimuli are combined with tactile or visual teaching stimuli indicating the direction of the sound source.

     (b) The role of head movements in the exploration of acoustic environments and implications for the rehabilitation of spatial hearing will be investigated.

     (c) Successful trainings strongly depend on the patients’ attention, motivation and endurance. CherISH will use training setups employing enriched auditory and visuo-auditory virtual (VR) and augmented realities (AR). The training will take into account patients’ personal preferences, traits, and emotional and motivational states. Machine learning (ML) will be used to tailor optimal training procedures (tasks, training schedule) for each patient.

The following INDIVIDUAL PROJECTS are available (visit also our website: https://cherish-network.eu/):

DC1: An assistive system is being developed for spatial hearing training in CI users. It decodes sound directions using an artificial neural network and provides tactile cues about sound direction. The system is tested in lab environments and controlled open-field experiments. EEG is used to study neuroplastic changes during the restoration of spatial hearing, University of Tübingen, Tübingen, Germany; supervisor: Prof. Dr. Christoph Braun.

DC2: A computational model of the neural processes involved in spatial hearing is developed:  The model is tested in normal hearing subjects and cochlear implants users. Features of the model are compared with physiological data recorded with EEG. University of Tübingen, Tübingen, Germany; supervisor: Dr. Stefanie Liebe.

DC3: Acoustic information processes more rapidly in cochlear implants compared to hearing aids, leading to a bias in the interaural time difference and sound localization when using both devices in combination. By adjusting the time difference through a delay in the cochlear implant signal, this bias can be corrected, eventually enhancing spatial hearing. University of Tübingen, Tübingen, Germany; supervisor: Prof. Dr. med. Hubert Löwenheim, Dr. med. Thore Schade-Mann.

DC4: The outcome of any training of spatial hearing is assumed to be closely related to head-movement behavior.  In order to test this hypothesis, the impact of head-movements strategies on auditory rehabilitation protocols will be investigated in patients in whom auditory cues are limited (patients with hearing aids) or compromised (normal hearing subject with altered auditory abilities). Furthermore, the project will examine to what extent these acquired regulatory skills entailing head-movements could transfer to more naturalistically-valid context reproduced in virtual reality (e.g., searching for sounds in complex audio-visual environments, such as a noisy street). Université Claude Bernard Lyon, Lyon, France; supervisor: Dr. Valerie Gaveau.

DC5: Sound localization is hypothesized to be closely related to the combination of visuo-spatial information and head movement strategies. In the project, the doctoral candidate will investigate whether this relation is altered in hearing impaired individuals (e.g., ageing adults with presbycusis, or hearing aid or cochlear implant adults and children). Furthermore, it will be studied whether head movement strategies will improve audio-visual integration and eventually sound localization capabilities, especially in situations where the auditory information is unreliably (i.e., in case of background noise). Finally, it will be investigated whether the use of head movement strategies to disambiguate spatial auditory cues in hearing-impaired patients depends on the severity of the hearing loss. Université Claude Bernard Lyon (UCBL), Lyon, France; supervisor: Dr. Valerie Gaveau.

DC6: This PhD project investigates the neuroplastic changes induced by training sound localisation skills. The project tests the transferability of laboratory findings to relevant real-life situations such as the localisation of approaching, potentially dangerous objects and the selective devotion of selective attention to single, spatially separated individuals in multi-speaker environments. Comparisons will be made between normal hearing and bilateral CI listeners.

This PhD project will lead to a deeper understanding of the cortical mechanisms that enable the improvement of spatial hearing abilities and will explore the possibilities and limitations of spatial hearing training in bilateral CI listeners. Austrian Academy of Sciences (ÖAW), Wien, Austria; supervisor: Dr. Robert Baumgartner.



DC7: In most training paradigms the sound sources change position in space based on the decisions of the experimenter or any automated stimulus presentation system. In this project, the effects of training will be examined when the participant actively moves the sound source. The working hypothesis is that active sensing could help re-learning because of (1) the predictive processing related to agency, (2) the continuous multisensory awareness about the position of the sound source in space. Different types of active sound source movements in normal-hearing participants are compared, focusing on vertical sound localization. To follow the dynamics of the learning and relearning process during training with self-controlled sound siource movements, the relearning of spatial hearing in sequentially implanted bilateral cochlear implant recipients is compared. Center for Mind/Brain Research (CIMeC), Trento, Italy; supervisor Prof. Dr. Francesco Pavani.

DC8: Most basic studies have used simple, single-channel stimuli to explore the perception of interaural time differences (ITD). This project will firstly overview and quantify the ITDs for natural broadband signals, and speech encoded across all stimulation channels. Secondly, we will implement enhancement by emphasizing temporal cues using the technical possibilities of new generation of CIs, which allow to perfectly synchronize both CI processors at the level of stimulation pulses in bilaterally implanted CI users. The enhanced cues will be realized at the temporal periodicities of the fundamental frequency F0 rate as well as at onsets and offsets in the speech envelope, modulation peaks and depths, and speech or speech-like stimuli on all-channels. Thirdly, the directional hearing sensitivities will be studied behaviorally, and electrophysiologically using electroencephalography. Katholieke Universiteit Leuven (KUL), Leuven, Belgium; supervisor: Prof. Dr. Jan Wouters, Prof. Dr. Tom Francart.

DC9: The ultimate goal of the project is the design of a prescription rule for jointly setting the parameters of the wide-dynamic range compression (WDRC) process used in hearing aids (HA) and CI.  The research will target simultaneously optimal speech understanding in noise and spatial perception. The inputs to the rule are acoustic measurements on the acoustic and electrical side of the devices. The research addresses the knowledge gap of how loudness perception varies in both modalities across a group of bimodal users that use a CI on one and a HA on the other ear. Initial feasibility studies will be performed. Cochlear Benelux (CBNL), Mechelem, Belgium; supervisor: Dr. Filiep Vanpoucke.

DC10: A system is developed and tested that modifies generated signals in a CI by compensating subject and environment-dependent deviations in the generated sound signal in real-time. An ‘enhanced’ CI provides a personalized and environment-adaptive correction of the CI, which optimizes acoustic cues for CI users. The system is tested and evaluated for technical feasibility and real-life implementation in various auditory environments involving spatial sound technology to simulate various near-to-real-life sound experiences. NEMO Labs (former 4D sound), Budapest, Hungary; supervisor: Paul Oomen.

DC11UK: An artificial intelligence (AI) based training consultant will be developed in order to optimize and personalize the training procedures for spatial hearing in CI-users. The project will use biographic data and personal features, such as individual hearing abilities, interests, preferences and traits to train an AI-based rehabilitation assistant that will suggest an optimal training. The quality of the training consultant will be validated. Imperial College London (ICL), London, United Kingdom; supervisor: Dr. Lorenzo Picinali. (Project not funded via HE/MSCA, but via UKRI)

DC12UK: Different training tasks and routines for spatial hearing with CIs will be designed and implemented using virtual-reality (VR) and real-life based conditions. Training tasks will be varied with respect to their involvement of procedural and perceptual learning. The efficiency of training procedures and the transfer of performance from VR to real-life conditions will be validated. Imperial College London (ICL), London, United Kingdom; supervisor: Dr. Lorenzo Picinali. (Project not funded via HE/MSCA, but via UKRI)

We plan to enroll all doctoral candidates by the end of September 2024.

More information on these individual projects and specific reuirements can be found on EURAXESS (https://euraxess.ec.europa.eu/jobs/search) in the individual job offer postings; To find them please enter the keyword CherISH into the search option.

Visit our website: https://cherish-network.eu/