| Business | Phone |
| Premier Research Laboratories 2000 N Mays St, Round Rock 78664 | (512) 238-7047 |
| Direct Packet Research Inc 575 Round Rock West Dr, Round Rock 78681 | (512) 238-9277 |
| Hearing Research Institute Inc 1930 Rawhide Dr, Round Rock 78681 | (512) 310-8950 |