Citation:

mOHAMED Shabana, B. C. Moore, Mostafa El-Khoust Mahmoud, Mona Selim, and M. Dokla, "Fast psychophysical tuning curves of the cochlea in normal hearing individuals", Advanced Arab Academy of Audiovestibulogy, vol. 1, pp. 12-17, 2014.

Abstract:

Introduction
Fast psychophysical tuning curve (fPTC) test is a fast computer-based method that aims to assess
the frequency selectivity of the cochlea and to detect the dead regions. It can quickly identify tip
frequency and Q10 of psychophysical tuning curves (PTCs) derived by using a band of noise
that changes in center frequency and a Békésy method to adjust the masker level required for
threshold of the noise. We applied this method in normal hearing individuals in the presence of
threshold equalizing noises at three signal levels. The sharpness of the PTCs (Q10) and the typical
shift of tips of the PTCs for 16 normal hearing individuals, when the tip frequency is estimated for
the average of a forward and reverse sweep, were obtained. The results were used to determine
the mean, SD, and 95% confidence interval of the shifts in normal hearing individuals.
Objective
The purpose of this experiment was to estimate the typical shift of tips of the PTCs for normal
hearing individuals. The results were used to determine the mean, SD, and 95% confidence
interval of the shifts. The sharpness of the PTCs change with signal level under conditions
where off-frequency listening is restricted, using a background noise, was also assessed. This
was performed to allow a comparison with the results of hearing-impaired patients tested at
the same level (but without background noise).
Study design
Sixteen adults of both sexes (eight male individuals and eight female individuals) were
randomly selected to establish normative data for the fPTC test. They were selected with
age ranging from 18 to 45 years. All individuals had normal middle ear function as indicated
by tympanometry and acoustic reflex measurement and by hearing threshold equal to or
better than 20 dB at octave frequencies in the frequency range (250–8000 Hz) (as defined
by ANSI S3.6-2004).
Keywords:
fast psychophysical tuning curves, Q10, tip frequency