COLUMBIA, MD: Deirdre Blackwood has joined media marketing and research firm Arbitron as SVP of corporate communications. Blackwood is responsible for consolidating the corporate communications function, which includes marketing communications, PR, and IR and further communications between the company and its stakeholders. She will report to Alton Adams, EVP and CMO at the company. Previously, Blackwood was VP of corporate communications and IR for TerraStar, a satellite-terrestrial telecommunications company. She has also served as the director of the Washington office of Burson-Marsteller.