Answering Machine Detection built for the sales floor

Accuracy depends on the vendor, the tuning and the call conditions, so no single number applies to every system. RizzDial AMD runs at 98% detection accuracy (based on RizzDial platform data, 2026) by running separate models at pickup, first audio, greeting and beep instead of relying on one listening window. Whatever vendor you evaluate, test it against a labeled sample of your own calls.

Silent call detection identifies when a person has picked up the phone but hasn't said anything yet, instead of treating that silence as a machine or an unknown result. RizzDial routes a detected silent answer to a live rep or AI agent so the conversation can start. Systems that don't handle this case often drop the call or leave the person on dead air.

AMD is the detection step: it decides whether a human, a machine, a fax, an IVR or a silent answer picked up. Voicemail drop is the action taken after AMD identifies a machine, playing a pre-recorded message or having an AI agent speak once the greeting ends. One detects, the other acts on what was detected.

AMD listens to the call as it connects and analyzes signals like line state, the onset of sound, speech cadence and tone. RizzDial runs a model at each of four stages, pickup, first audio, greeting, and beep/end of message, so a decision doesn't rest on one long listening window. The result determines whether the call goes to a rep, an AI agent, or a voicemail drop.

Speed depends on the system and how it is tuned. RizzDial detects voicemail in 0.66 ms (based on RizzDial platform data, 2026). Twilio's AMD docs do not publish a detection time; they document a 30 second default MachineDetectionTimeout and note that pushing for faster responses increases the rate of unknown results.

Most AMD engines classify by the length and rhythm of the greeting, so a live person with a long greeting, such as a business answering with its name, can read as a machine. A person who picks up and stays silent can also be written off as unknown and disconnected. Those are the errors that turn a real person into an abandoned call under the FTC and FCC rules, which is why RizzDial treats a silent answer as a live pickup.

That's a silent answer: the line connects but no greeting or speech follows. Many systems classify this as unknown or simply hang up, since there's nothing to match to either a human or a machine pattern. RizzDial reads it as a live pickup signal and connects the person to a rep or AI agent instead.

Yes. An AI agent needs to know what's on the other end of the line before it speaks: a live person gets the opening line immediately, a machine gets a message timed to the beep, and a silent answer still gets an opening line instead of dead air. AMD is what makes that decision for the agent in real time.

AMD is widely used in outbound calling, but how a dialer acts on the result falls under the FTC Telemarketing Sales Rule (16 CFR 310.4(b)(4)) and the FCC TCPA rule (47 CFR 64.1200(a)(7)). Both cap abandoned calls at 3 percent of calls answered by a live person, per campaign over a 30 day period, and a call counts as abandoned if the person is not connected to a live rep within 2 seconds of their completed greeting. AMD errors that disconnect live people count against that limit. This is general information, not legal advice.

Synchronous AMD makes the dialer wait for a detection result before doing anything else with the call. Asynchronous AMD, available in Twilio via AsyncAmd=true with an AsyncAmdStatusCallback, lets the call proceed while the detection result is delivered separately to a callback, so the call flow isn't blocked on the detection decision.

Yes. A fax machine produces a distinct tone rather than speech, so it is recognized as a non-human answer and no rep or AI agent is connected. An IVR or phone tree is also treated as a non-human answer and logged, then handled by your campaign rules, for example routed to a rep who can work the menu or set for a later retry.

Build a labeled sample of calls with known outcomes (live answers, voicemail, silent pickups, fax and IVR lines), run them through the AMD you are evaluating, and score each result against the truth. Track false machines and false humans separately because they cost you different things. Our testing guide walks through building that test set and reading the results.

Yes. Twilio offers AMD as a feature of Twilio Programmable Voice, enabled per call with MachineDetection=Enable or MachineDetection=DetectMessageEnd, with tunable parameters for timeout and speech thresholds. It's a detection API: pacing, agent routing and voicemail drop logic have to be built by the developer on top of it.

A false positive, often called a false machine, is when AMD labels a call as a machine (or as unknown) when a live person actually answered. It is the costly error: a real conversation never happens, and under the FTC and FCC rules a live person who is not connected to a rep within 2 seconds can count as an abandoned call. The opposite error, a false human, sends a rep to a voicemail greeting and wastes their time.