Spirit Acoustics has installed the Speech Guard System to improve the office-to-office isolation in the Ortho Biotech facil­ity. The drop-tile acoustical ceiling was identified as the flanking path, providing for poor speech isolation. Spirit Acoustics installed Shield Guard Tile Backers on the top of the ceiling tiles to provide increased transmission loss. In addition, Speech Guard light hoods were installed above the light fixtures to reduce this flanking path. Finally, in some spaces wall treatment in the form of fabric-covered glass fiberboard had been applied. Our measurements indicate that these various applications have provided a significant improvement in the isolation between spaces.