product Siemens Hearing Instruments Inc, Piscataway, NJ, offers the PRISMA™ 2 family of four channel digital hearing instruments with optimized compression control and output limiting. The PRISMA 2 features improved performance of its directional microphone system, and includes a new feedback management system, improved voice activity detection, and acoustic indicators for program change and power management. (800) 766-4500; www.siemens-hearing.com/pro.