  The spectra of the nucleons, $\Delta$ resonances and the strange hyperons are
well described by the constituent quark model if in addition to the harmonic
confinement potential the quarks are assumed to interact by exchange of the
$SU(3)_F$ octet of pseudoscalar mesons, which are the Goldstone bosons
associated with the hidden approximate chiral symmetry of QCD. In its $SU(3)_F$
invariant approximation the pseudoscalar exchange interaction splits the
multiplets of $SU(6)_{FS}\times U(6)_{conf}$ in the spectrum to multiplets of
$SU(3)_F\times SU(2)_S\times U(6)_{conf}$. The position of these multiplets
differ in the baryon sectors with different strangeness because of the mass
splitting of the pseudoscalar octet and the different constituent masses of the
u,d and s quarks that breaks $SU(3)_F$ flavor symmetry. A description of the
whole spectrum, to an accuracy of $\simeq$ 4\% or better, is achieved if one
matrix element of the boson interaction for each oscillator shell is extracted
from the empirical mass splittings. The ordering of the positive and negative
parity states moreover agrees with the empirical one in all sectors of the
spectrum. A discussion of the conceptual basis of the model and its various
phenomenological ramifications is presented.
