  Using molecular dynamics simulation, we study acoustic resonance in
low-temperature glass by applying a small periodic shear at a boundary wall.
Shear wave resonance occurs as the frequency $\omega$ approaches $\omega_\ell=
\pi c_\perp\ell/L$ ($\ell=1, 2, 3,...)$. Here, $c_\perp$ is the transverse
sound speed and $L$ is the cell length. At resonance, large-amplitude sound
waves appear after many cycles even for very small applied strains. They then
induce plastic events, which are heterogeneous in space and intermittent on
time scales longer than the oscillation period $2\pi/\omega$. From these
irreversible particle motions, there arises strong dissipation suppressing the
growth of sounds. After many resonant cycles, we observe a phenomenon of forced
aging, where the shear modulus (measured after switching off the oscillation)
is increased significantly.Sometimes, exceptionally large plastic events and
system-size sliding motions induce a transition from resonant to off-resonant
states. At resonance, translational diffusion becomes appreciable as well as
aging due to enhanced configurational changes.
