Ultrasound phased array apparatuses (including systems and devices) and methods for making and using them. These apparatuses may be thin, and lightweight, so that they may be worn on a subject's head or other body region in acoustic communication so as to deliver ultrasound for stimulation of tissue, and particularly for neurostimulation. The ultrasound phased array apparatuses may be used as wearable and lightweight neurostimulation apparatuses.
