One embodiment of a rigid fixture for coupling one or more transducers to the center upper back of the human body. The left contact area (10) and right contact area (11) are curved surfaces designed to ergonomically fit against the trapezius muscle groups. The contact areas (10) and (11) may optionally be covered with a cushioning pads (31). Between the contact areas (10) and (11) is a center section spaced away from the spine (12) that is not in contact with the human body. One or more transducers (30) are attached or incorporated into the center section (12), which may be facilitated by transducer attach points (21). The entire fixture can be fastened to straps, belts, harnesses, backpacks, clothing, or seats by the attach points (20).