What is the least count of an audiometer?

Answer 1

The LEAST count would be Zero (0). This is not trivial. There is an established standard for what Zero actually is, as a reference point in Air.

BS EN ISO 389 (1997) "Acoustics. Standard reference zero for the calibration of pure tone air conduction audiometers"

Answer 2

The least count of an audiometer typically ranges from 1 to 5 decibels, depending on the specific model and features. This represents the smallest increment of sound intensity that can be measured and is important for accurate hearing assessments and calibrations.