Schematic view of the profiles of the (modified) Brunt–Väisälä and Lamb frequencies as a function of the radius normalized by the radius of the base of the convective zone, r_b. The value of ν_max in the case of Type-a and Type-b evanescent regions, as well as at the transition between both regimes, are indicated by the orange, magenta and red dashed lines, respectively. The black dots correspond to the turning points for the three cases. The magenta domain delimits all the possible locations of the evanescent regions in the transition regime.