The wall that must fall is the thin web of membrane dividing the left brain from the right, the veil sealing the carnal mind away from the divine mind on the higher side. Jericho, whose name breathes fragrance, is that right hemisphere where the inner light is seen, walled against you until the energy has risen. The saviour within, bearing the same name as Joshua, circles that barrier 7 times, once for each of the 7 nerve centers set like resistors along the spine.
The long silence is not restraint for its own sake. In deep stillness the current gathers, and the mouth stays shut because the power is not yet full. Only when the 7th center opens does the shout come, and the membrane gives way, so the higher mind floods the lower and the 2 halves become one.
Wall of Jericho: the web of membrane between the left and right hemispheres, the veil that seals the carnal mind away from the divine mind
Jericho: the right hemisphere, the fragrant place where the inner light is seen face to face
Joshua: the saviour within, the higher self that leads the inner powers up through the body
7 days of marching: the climb through the 7 nerve centers ranged along the spine, opened one at a time
Rams' horns: the sound at each center that trips it open and lets the energy pass higher