High frequency Bekesy audiometry. I: equipment and calibration

Area of Science:

• Audiology
• Medical instrumentation
• Hearing diagnostics

Background:

• The Grason-Stadler E-800 Bekesy audiometer is a standard tool for hearing assessments.
• Existing limitations may restrict its utility for high-frequency (HF) range testing.
• Cost-effective solutions are sought for expanding diagnostic capabilities in audiology.

Purpose of the Study:

• To describe a simple, inexpensive conversion of the Grason-Stadler E-800 Bekesy audiometer.
• To extend the high-frequency (HF) range of the audiometer up to 20 kHz.
• To provide a cost-effective method for obtaining HF diagnostic information.

Main Methods:

• Modification of the Grason-Stadler E-800 Bekesy audiometer.
• Incorporation of a 1/2-inch condenser microphone as a transducer.
• Utilizing an adjustable headband for coupling the microphone to the ear canal.
• Free field calibration recommended for accuracy.
• Detailed instructions for conversion and calibration provided.

Main Results:

• The modified system achieves a dynamic range of 135 dB.
• Prototype unit calibrations demonstrated acceptable stability and validity.
• The conversion is straightforward and inexpensive.

Conclusions:

• The modified HF E-800 audiometer is a valuable tool for audiologists.
• It provides a cost-effective source of high-frequency diagnostic information.
• This modification enhances the utility of existing audiometric equipment.