update README

Signed-off-by: Pedro Veloso <pedro.n.veloso@gmail.com>
remove Stereo listener on destroy

Signed-off-by: Pedro Veloso <pedro.n.veloso@gmail.com>
better preferences handling. set preferences for future functionality

Signed-off-by: Pedro Veloso <pedro.n.veloso@gmail.com>
implement earplug start verification

Signed-off-by: Pedro Veloso <pedro.n.veloso@gmail.com>