In the race to make cell phones and other audio devices smaller and cheaper, one company has found a way to put the sensing and processing onto a single chip. Akustica, a Pittsburgh spinoff from Carnegie Mellon University, has built multiple microphones onto a chip by etching meshes of tiny beams over cavities in its surface and applying a polymer coating that vibrates. Unlike competing systems that require separate assemblies for processors and acoustic parts, each of these chips is fabricated in one piece using standard automated techniques. The chips are, therefore, durable, reliable, and cheap to mass-produce. Akustica has put as many as 64 microphones onto a two-by-two-millimeter signal processor about the size of a sesame seed. Considerably smaller than what’s inside today’s cell phones and hearing aids, the chip, says CEO Jim Rock, can tell where sounds are coming from and can reduce background noise for a fraction of conventional manufacturing costs. Akustica plans to begin volume production within two years.