- "They called you the Emperor's Voice. Do Barrayarans really believe their emperor's voice comes from your mouth, across all those light-years?”
Miles regretted his inability to lean back in a chair; he straightened his spine a trifle instead. “The name is a legal fiction, not a superstition, if that's what you're asking. Actually, Emperor's Voice is a nickname for my job. My real title is Imperial Auditor—a reminder that always my first task is to listen. I answer to—and for—Emperor Gregor alone." - ―What is the Emperor's Voice, really?[src]
A Voice was a Barrayaran legal concept of proxy which bestowed the hierarchical authority of one person upon another of otherwise lesser rank. This bestowed authority was plenipotentiary, but applied only where the person of lesser rank was carrying out his formal duties. In addition, most subjects endowed with their superior's Voice tended to be circumspect about its power.
Imperial Auditors spoke with the Emperor's Voice[1][2], for instance. Lord Miles Naismith Vorkosigan was granted his father Count Vorkosigan's Voice to investigate a murder.[3]
Cetagandans had a similar concept with their Emperor, though less legal and more ceremonial, in which an official would relay messages such as thanks to others "with his Breath and Voice," to imply the supreme importance without the Emperor physically having to be there.