Spoken when the session cannot start at all — a provider failed to open, so
there is no conversation to have (pipeline mode).
STT and TTS open concurrently and each goes live on its own, so the common
case is that TTS connected and STT did not: the agent has a working voice and
nothing to listen with. Saying nothing leaves the caller holding a line that
sounds connected and never responds — indistinguishable, from their side,
from a dead call. One sentence tells them to hang up and try again, which is
the only useful thing left to do. Set startFailurePhrase: "" to disable.
Spoken when the session cannot start at all — a provider failed to open, so there is no conversation to have (pipeline mode).
STT and TTS open concurrently and each goes live on its own, so the common case is that TTS connected and STT did not: the agent has a working voice and nothing to listen with. Saying nothing leaves the caller holding a line that sounds connected and never responds — indistinguishable, from their side, from a dead call. One sentence tells them to hang up and try again, which is the only useful thing left to do. Set
startFailurePhrase: ""to disable.