Basic study on the measuring of fatigue by the minimum audible pressure

Area of Science:

• Audiology
• Occupational Health
• Human Factors Engineering

Background:

• Visual display terminal (VDT) work is prevalent, leading to significant sensory stimulation and potential fatigue.
• Current methods for measuring VDT work fatigue, such as the critical flicker fusion (CFF) value, have limitations.
• There is a need for reliable and practical methods to quantify fatigue, particularly hearing sense fatigue, to regulate working hours.

Purpose of the Study:

• To introduce and validate a novel system for measuring fatigue induced by VDT work.
• To establish the minimum audible pressure (MAP) fluctuation as a practical index for assessing hearing sense fatigue.
• To determine optimal parameters for measuring MAP fluctuations.

Main Methods:

• The study developed a new system measuring the fluctuation in minimum audible pressure (MAP).
• An increase in the threshold value of MAP was used as the index for fatigue.
• Experiments involved pure tones (1,000 Hz) and standard hearing acuity tests using headphones (Telephonics, TDH39, MX41/AR) with a method of limits.

Main Results:

• The optimal rate for increasing and decreasing audible pressure was determined to be 2 dB or 1 dB.
• Experimental results demonstrated that MAP fluctuations can be reliably measured.
• The study confirmed the feasibility of using MAP as a practical index for hearing sense fatigue.

Conclusions:

• The proposed MAP fluctuation measurement system is a viable and practical tool for assessing hearing sense fatigue.
• This method can serve as an objective index for fatigue related to VDT work.
• Further application of this technique can help in establishing guidelines for VDT work duration and managing occupational fatigue.