> For the complete documentation index, see [llms.txt](https://docs.bird.com/connectivity-platform/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.bird.com/connectivity-platform/how-to-guides/set-up-answering-machine-detection.md).
# Set up answering machine detection
When making an outbound call with Flow Builder, your call will sometimes reach an answering machine instead of being answered by a human. Reaching an answering machine is different from a failed, busy, or answered call, so you’ll want your flow to behave differently!
### How the branch works
When you add the **Answering machine** branch to your flow, a short “silence” period will be added to the beginning of each phone call. During this “silence”, the flow will listen to the response on the other end to decide if it is dealing with a real human or an answering machine/voicemail. Once this has been established, the flow will route the call accordingly.
### Set up answering machine detection
1. To set up answering machine detection in a flow that uses the **Outbound call** step, go to the step settings and toggle **Answering machine detected** to ‘on’.
2. If you want to set your flow up to leave a voicemail, toggle the **Wait for voicemail greeting** button to ‘on’.
3. If you want to terminate the call as soon as an answering machine is detected (which means you haven’t reached a human), toggle the **Wait for voicemail greeting** button to ‘off’.
4. If you want to improve the accuracy of the answering machine detection, increase the **Detection time in seconds**. Remember, the longer the detection time, the longer the “silence” period will be when the phone call starts. Humans can get frustrated by a long silence, and it will make them more likely to hang up. 5 seconds is the industry default.
5. Great, now all you have to do is decide what action you want your flow to take when it detects an answering machine, and add this to your flow!
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