The morphogenetical topology optimization method shapes the scattering inclusions, shown as gray material. When the ARE is excited by monopolar source emitting broad-band white noise, the radiated sound creates an acoustic rainbow. The source is positioned at the center of the emitter (illustrated using white light) and driven with equal power at all frequencies from 7,600 to 12,800 Hz. The experimentally measured acoustic output (far field) is mapped to the visible spectrum of light by its magn...