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Andrej Kral, MD, PhD

Member, German National Academy of Science

Professor of Auditory Neuroscience (Hannover)

Professor of Systems Neuroscience (Sydney)

Adj. Professor of Cognition & Neuroscience (Dallas)

➤ Highlights of the lab

➤ Collaborations

Dr. Peter Baumhoff

Dr. Wiebke Konerding

Dr. Rüdiger Land

Dr. Daniel Schurzig

Adrian Armstrong, MSc.

Brilliant, MSc.

Monique Hajduk, MUC.

Ward Hamidey, MUC.

Valerie C. Cholewa, MUC.

Nova Resfita, MSc.

Xue Wang, MSc.

Manuela Chambers

Lisa Kötter

Daniela Kühne

Our research is focused on „nature and nurture“ in brain development, on developmental consequences of deafness, methods of its compensation by neuroprostheses and the adaptation of the brain to the neuroprosthetic stimulation. So far, the cochlear implant has been the clinically most successful neuroprosthetic device. We work on its further improvements and search for alternative ways of the stimulation of neurons in general, including stimulation within the central auditory system and the brain.
As brain development depends on experience, the most devastating effects on the brain are observed when hearing loss sets in during childhood. We could show that in congenitally deaf animals feature sensitivity and representation of auditory space are degraded, indicating degraded disrcimination ability. Formation of auditory categories (“objects”), control of auditory plasticity (learning) and integration of sensory input into ongoing cortical activity are further compromised, partly due to the malfunction of auditory microcircuits. These deficits lead to the inability to compute errors between prediction about sensory input and actual sensory input and interfere with top-down interactions in the cortex. This prediction error drives learning in hearing-competent adult subjects. In congenital deafness, some of the auditory cortex is even recruited for non-auditory function (cross-modal reorganization). Congenital deafness consequently leads to widespread brain adaptations, including higher-level functions, as suggested by the connectome model of deafness. When hearing restoration takes place late in life, auditory learning capacity is reduced and deficits in representation of auditory input persist. We discovered the neural correlate of sensitive (critical) periods for cochlear implantation: the earlier in life cochlear implantation is performed, the faster and better is the adaptation of the primary auditory cortex to the implant and the more extensive is the compensation of the deficits induced by congenital deafness. We could uncover several neural mechanisms responsible for such sensitive periods.
Recently, we described a reorganized brain representation of the ears following inborn single-sided deafness and were the first to demonstrate its neural correlate and a sensitive period for its therapy. It likely constitutes a clinical syndrome that we suggested to call aural preference syndrome. First data from implanted kids with single-sided deafness by many centers around the world support this suggestion.

Outcomes of therapy of hearing are still characterized by large variability. Our goal is to built the scientific base for a comprehensive differential diagnosis and therapy of sensory loss tailored to the needs of the individual subject, by that eliminating this variability. Our research focuses on cochlear health and on the variability of the microanatomy of the human cochlea. Our research has recently provided a tool for virtual cochlear implantation with a given cochlear implant in the given (individual) patient cochlea. For the first time this allows to predict which electrode optimally fits the given subject‘s cochlea.

Prof. Andrej Kral, MD, PhD

Chair & Professor

Dept. of Experimental Otology, Hannover Medical School

Cluster of Excellence Hearing4All

Stadtfelddamm 34

D-30625 Hannover, Germany

Email:

Lab funding:

„Deutsche Forschungsgemeinschaft“

(DFG)

European Union

National Science Foundation, USA

(collaboration with DLR, Germany)

German Academic Exchange Service

(DAAD)

Industry & foundation grants:

MedEl Corp., Innsbruck, Austria

Oticon Medical, Denmark

William Demant Foundation

Advanced Bionics GmbH, Germany

News:

September 2024:
A. Kral appointed honorary member of the Austrian ENT society.

August 2024:
Paper published on the role of friction forces during cochlear implantation. Paper

July 2024:
Paper on excitatory-inhbitory balance changes in congenital single-sided deafness pub-lished. >>> Link

June 2024:
> 10.000 citations in Google scholar for A. Kral

Mai 2024:
Alpha-gamma cross-frequency coupling in auditory cortex extensively reduced in conge-nital deafness. Paper

February 2024:
Prestigious ARO Pioneer Award recieved.

February 2024:
Study on EEG oscillatory signatures of cognitive and sensory load published. Paper

February 2024:
Neonatally-deafened adult rats demonstrate hyperactivity, ex-cessive play, impaired concept learing and functional changes in frontal cortex. Paper

January 2024:
Language reception of binaurally implanted con-genitally deaf children. Paper

Student introductory text-book for Neuroprosthetics >>> Link

„The Lady and the Unicorn: Hearing“.

Unknown flamish artist, 15th century.

Andrej Kral (left) and Steve Lomber (right)

ARO Midwinter Meeting 2024, Los Angeles, CA, USA