Purpose: An air conduction audiometer was developed for basic hearing screening. This study introduces the hardware platform and development technologies. Methods: The developed platform includes a pure tone generator and tone switching method, which is capable of customizing the test frequencies and adjusting pure tone output level. Results: The developed audiometer was evaluated its performance according to the international standards. The pure tone output level was compared with conventional products. The attenuator shows good linearity with a deviation of ±0.2 dB. The output tone has a frequency error under ±1% and total harmonic distortion of 0.44%. Additionally, the audiometer was evaluated in terms of on/off ratio, crosstalk and rise/fall time during tone switching. Conclusion: Through audiometer development, we expect to increase the understanding of pure tone audiometric device and calibration knowledge.