  In the last decade the quality and the amount of observational asteroseismic
data that has been made available by space based missions had a tremendous
upgrowth. The determination of asteroseismic parameters to estimate the
fundamental physical processes occurring in stars' interiors, can be done today
in a way that has never been possible before. In this work we propose to
compute the seismic observable $\beta$, which is a proxy of the phase shift of
the acoustic modes propagating in the envelope of the Sun-like stars. This
seismic parameter $\beta$ can be used to identify rapid variation regions
usually known as glitches. We show that a small variation in the structure,
smaller than 1% in the sound speed, produces a glitch in the acoustic potential
that could explain the oscillatory character of $\beta$. This method allows us
to determine the location and the thickness of the glitch with precision. We
applied this idea to the Sun-like star $\alpha$ Centauri A and found a glitch
located at approximately $0.94\,R$ (1400 s) and with a thickness of 0.2% of the
stars' radius. This is fully consistent with the data and also validates other
seismic tests.
