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3.7.12 Threshold Determination using the Ascending Method
Manual or reversed pulses may be used. If manual pulses are used, they should be
at least one second in duration.
1) Present a tone which is 10dB lower than the threshold obtained during the
familiarization procedure. If the response fails, increase in 5dB steps until the subject
responds.
2) Decrease by 10dB and begin another ascending level series. Continue with this
until three out of a maximum of five responses at the same level occur.
Almost the same results will be obtained, when two responses out of three tone
presentations occur at the same level and frequency. If less than two responses out
of three (or less than three out of five) have been obtained at the same level, present
a tone 10dB higher than the last response and repeat the procedure.
3) Proceed to the next frequency. Decrease the level by 10dB and begin another
ascending level series. Continue until you get three out of five responses at the
same level.
4) Repeat the familiarization procedure. If the difference is 5dB or less move on to
the next ear. If the difference is 10dB or higher, repeat the test at further frequencies
in the same order until agreement to 5dB or less has been obtained.
5) Proceed until both ears have been tested.
