He did his medical training and otolaryngology residency in Hacettepe University Medical Faculty in Ankara. In 1996 He became associate professor, and in 2003 professor in the same department. He was a research scholar in House Ear Institute, Los Angeles California where he performed a temporal bone study on middle fossa approach (1997).

For the last 30 years, he has been practicing only otology and neurotology. His main academic interest is inner ear malformations. He was involved in the classification and surgery of inner ear malformations. He has recently updated his classification system of inner ear malformations (2009, 2013 and 2017). He developed an electrode for malformations. Recently he performed a histopathological study on inner ear malformations trying to explain the pathophysiology of developmental inner ear anomalies (2016). As Hacettepe Implant Team they performed over 3546 implants until May 2026. They also started auditory brainstem implantation in prelingually deafened children in 2006. So far Hacettepe team performed 205 ABI in children.

He has 164 articles in English language in peer reviewed journals.

He was the president of the Otology and Neurotology Society in Turkey between 2008 and 2010. He was the chairman of the Department of Otolaryngology in Hacettepe University between 2006 and 2011. During this time 4 year-Audiology Undergraduate Program was set up in Hacettepe University.

Professor Thomas Klenzner, MD, is Deputy Director of the Department of Otorhinolaryngology and Head of the Hörzentrum (Hearing Centre) at University Hospital Düsseldorf, Heinrich Heine University Düsseldorf, Germany.

At University Hospital Düsseldorf, he co-founded and developed the Hörzentrum into a specialised centre for implantable hearing devices, cochlear implantation, and comprehensive auditory rehabilitation. His clinical work focuses on otologic and lateral skull-base surgery, including hearing rehabilitation after vestibular schwannoma treatment. Before joining Düsseldorf, he studied medicine at Hannover Medical School and trained and worked in otorhinolaryngology at the University Medical Center Freiburg, where he completed his habilitation.

His clinical and research interests include cochlear implantation, auditory rehabilitation, minimally traumatic otologic and lateral skull-base surgery, vestibular schwannoma, computer-assisted surgery, and medical robotics. He is a Past President of CURAC (German Society for Computer- and Robot-Assisted Surgery) and a member of several professional societies. Professor Klenzner is a regular faculty member at international cochlear implant surgical courses and numerous international congresses. He has authored or co-authored more than 100 peer-reviewed publications and delivered more than 200 national and international presentations.