Funding for this research was provided by:
National Science Center (2012/05/N/NZ5/02629)
Received: 24 April 2019
Accepted: 6 August 2019
First Online: 14 August 2019
Ethics approval and consent to participate
: The study was approved by the bioethics committee at the Institute of Physiology and Pathology of Hearing and performed according to the Declaration of Helsinki. Written informed consent was obtained from each participant.
: A consent for publication has been obtained.
: The authors declare that they have no competing interests.