Picking the right one matters more than any prompt you will write. A two-way conversation costs roughly three times a one-way announcement — so the question is never which is best, it is whether the answer changes what happens next.
See rates by planA live pipeline — speech in, model, voice out — running continuously while the call is open.
Best for answers you do not already have — qualifying, screening, finding out why.
Plays a message and hangs up. No speech recognition, no model call, no per-call AI cost.
Best for notifications and reminders where a reply changes nothing.
“Press 1 to confirm, 2 to reschedule.” The digit is captured exactly, with no transcription to get wrong.
Best for one choice from a short, fixed list.
Not by which sounds most impressive. The test is whether the reply changes the next step.
| If you need to… | Use | Because |
|---|---|---|
| Understand what someone means | Conversation | Only free speech captures a reason |
| Tell people something | Announcement | A reply would change nothing |
| Get one choice from a short list | Keypad | A digit is unambiguous and cheap |
| Confirm, reschedule or cancel | Either | Keypad if the options are fixed |
| Handle a complaint | None — use a person | Judgement and authority are required |
Conversation buys understanding and pays in latency. A turn is silence detection, then the model, then the voice — under two seconds when tuned, never zero. Where the time actually goes.
Announcement buys reach and pays in goodwill. It is the only channel that reliably interrupts, which stops being true the moment it becomes routine. One per customer per month is a sane ceiling; weekly gets your number blocked.
Keypad buys certainty and pays in flexibility. Keep menus to three or four options — nobody remembers six, and a caller who mishears option four presses nothing at all.
A clinic sends a one-way reminder two days out and a keypad confirm the evening before, reserving conversation for patients who press the reschedule digit. A lender announces the EMI date, then calls conversationally only the accounts that miss it.