Low Frequency Hearing Thresholds in Pressure Field and in Free Field

Thresholds of hearing Were determined in pressure field at frequencies from 4 Hz to 125 Hz. At the frequencies 4–25 Hz hearing thresholds were found that are in the lower middle of the range already reported by other investigators. At frequencies from 25 Hz to 1 kHz thresholds have already been determined in free field by the same method and using the same subjects. The two investigations overlap at frequencies from 25 Hz to 125 Hz, and in this range the results were almost identical. The differences were below 1 dB, except at 63 Hz where the difference was 2.5 dB. None of the differences was significant in a t-test.