Answering Machine Detection (AMD)
Run outbound campaigns3 min readUpdated 2026-03-14
Answering Machine Detection analyzes the first few seconds of a connected call to determine whether a live person or a voicemail system answered. When AMD detects a machine, it can automatically drop a voicemail or skip the call — keeping agents focused on live conversations.
Available on: Predictive Dialer campaigns only. Requires SalesPro plan ($249/user/mo).
How AMD Works
- The Predictive Dialer connects a call.
- AMD listens for 4–5 seconds, analyzing speech patterns.
- If AMD detects a live person, it routes the call to an available agent.
- If AMD detects a machine, it either drops a voicemail or disconnects, based on your settings.
Accuracy and Limitations
| Metric | Value |
|---|---|
| Accuracy | ~75% |
| Detection delay | 4–5 seconds |
| False positives | ~25% of the time, AMD may misclassify a live person as a machine (or vice versa) |
What this means in practice:
- Live prospects may experience a 4–5 second delay before hearing an agent. Some will hang up during this window.
- Approximately 1 in 4 calls may be misclassified. A live person may get a voicemail drop, or a machine may be routed to an agent.
Enabling AMD
- Open a Predictive Dialer campaign (new or existing).
- In campaign settings, toggle Answering Machine Detection to On.
- Configure what happens when a machine is detected:
- Drop voicemail after beep — Plays your pre-recorded voicemail message automatically.
- Disconnect — Ends the call without leaving a message.
- If using voicemail drop, select the recording from your Voicemail Drop library.
Voicemail Drop After Beep
This feature requires AMD enabled. When AMD detects a machine:
- JustCall waits for the voicemail greeting to finish and the beep to sound.
- Your pre-recorded message plays automatically.
- The call disconnects after playback.
No agent action is needed. Set this up in campaign settings under AMD > Voicemail Drop After Beep.
When to Enable AMD
| Enable AMD when... | Disable AMD when... |
|---|---|
| You have large contact lists and want to maximize live conversations | Your connect rates are high and few calls go to voicemail |
| Agents are expensive and idle time matters | The 4–5 second delay is unacceptable for your prospects |
| You want automatic voicemail drops | You prefer agents to handle voicemails manually |
Best Practices
- Monitor your connect-to-agent rate with AMD on vs. off to measure impact.
- Pair AMD with Voicemail Drop After Beep so machine-detected calls still leave a message.
- If prospects complain about silence at the start of calls, consider reducing parallel lines instead of disabling AMD.
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