Audiometer device design with integration of different sources = Farklı kaynaklara entegre işitme cihazı tasarımı

Audiometry is the technique to identify the nature of hearing loss and to determine the threshold of hearing by recording responses of the patient after presenting him with auditory stimuli with varying intensity levels. There are different audiometric techniques and procedures used for achieving this. The vast majority of medical devices found in the marketplace as a commercial product for the field of audiology have been developed for clinical limited testing. These devices cannot be used for purposes other than those specified by the manufacturer. This has serious limitations in the experimental design of scientific research carried out in limited budget training research hospitals, and it reduces the quality of the research that is revealed. With the circuit designs that can be integrated externally to the devices used in the audiology clinics, the capabilities of these devices can be increased and the usage capacity can be increased in line with the requirements of the clinician or researcher. In this study, an audiometer is designed and prototyped to generate pure tone, control both audio channels separately, control audio sources connected from external input. The pure tone produced or the audio signal from the external source is routed through switches and transmitted to the patient through the attenuator circuit. Device control is performed by STM32F746 development kit. The device has three different modes as manual test automatic, pure tone threshold test and volume control. In manual mode, the operator can send pure tone signals to the patient's ear at a frequency of 250 Hz - 8000 Hz and a range of 0-110 dB with 1 dB sensitivity. According to the responses taken from the patient response button, an audiogram is created simultaneously on the device screen. In addition, masking white noise and pink noise with sound-loaded on the memory card can be used. The Hughson Westlake method was used as the automatic test method. After the test is started, hearing threshold values are recorded according to the test procedure. An audiogram is created simultaneously on the screen during the test. In the audio control mode, the audio signals from the external source can be independently controlled 1 dB in two channels. This audiometer helps contribute to academic studies. Moreover, this has been used in graduate-degree theses in Audiometer branch of Otology in the Faculty of Medicine in Dokuz Eylul University. Developed audiometer is also almost ready to manufacture as a commercial device after some procedures for international test and calibration. Research Fund of the İzmir Katip Celebi University supported this work. Project Number: 2016-TYL-FEBE-0031.