| # | Company name | Role | # of Projects |
|---|---|---|---|
| 1 | ACAD-International AB | acoustics consultant | 7 |
| 2 | Accord Acoustique | acoustics consultant | 2 |
| 3 | Acentech | acoustics consultant | 5 |
| 4 | Acoustical Design Group, Inc. | acoustics consultant | 2 |
| 5 | Acoustic Dimensions | acoustics consultant | 4 |
| 6 | Acoustic Logic | acoustics consultant | 8 |
| 7 | Acoustic Logic Consultants | acoustics consultant | 5 |
| 8 | AcoustiCORK Products | acoustics consultant | 1 |
| 9 | Acoustics by JW Mooney | acoustics consultant | 1 |
| 10 | Acoustique et Conseil | acoustics consultant | 12 |
| 11 | Acoustique Vivié et Associés | acoustics consultant | 1 |
| 12 | Acústica & Sônica | acoustics consultant | 9 |
| 13 | Acviron Acoustic Consultants Private Limited | acoustics consultant | 2 |
| 14 | ACV SA | acoustics consultant | 1 |
| 15 | Adrian James Acoustics | acoustics consultant | 0 |
| 16 | Aercoustics Engineering Ltd | acoustics consultant | 3 |
| 17 | ÅF-Ingemansson AB | acoustics consultant | 7 |
| 18 | A. Harold Marshall | acoustics consultant | 1 |
| 19 | Aharon Viks | acoustics consultant | 1 |
| 20 | Aislamientos Sisplanor | acoustics consultant | 6 |