Hi Folks. I am delivering a full fledged outreach system for a Real Estate client, and it is working well. However, there is some issues with the voicemail detection. Sometimes, the message in the voicemail is different, shorter and less clear, hence I get the ended reason being customer-ended-call (for some reason it just stops after 7-8 seconds in those cases). Is there any Vapi expert here that has been struggling with Voicemail using Twilio and found a good solution? Would really be happy to hear you guys input on that.

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@Shubham Bajaj can you please help? I'm clicking on " ask for help " but it says "this interaction failed "

Hey @Benjamin E. can you enable twilio voice mail for your assistant and they try? FYI: if you don't se the voicemail messages then voicemail calls won't end with reason voice-mail-detected. Enable this for your assistant and it will work.

json
  "voicemailDetection": {
    "provider": "twilio",
    "enabled": true,
    "voicemailDetectionTypes": [
      "machine_end_beep",
      "machine_end_other",
      "machine_end_silence",
      "machine_start",
      "unknown"
    ],
    "machineDetectionTimeout": 5,
    "machineDetectionSpeechThreshold": 2400,
    "machineDetectionSpeechEndThreshold": 1000,
    "machineDetectionSilenceTimeout": 3000
  }

Do let me know how it goes.

Hi @Shubham Bajaj Thank you for your response. So actually, I've done this yesterday, and I am not sure if it helps or not. What happens is, sometimes, the voicemail annoucement of my phone number is different and less clear, and my agent thinks it's a human responding and not the actual voicemail annoucement, so it starts speaking the script, and then it stops at 8 seconds. Super strange. Here is an example recording of the problem: https://jtuyprjjgxbgmtjiykoa.supabase.co/storage/v1/object/public/recordings/d5f08bde-0947-4ff8-9d8e-6666cb8daa75-1731461503552-17207616-a5d9-4250-b795-8d4bf1367698-mono.wav Here is another example of a problematic use case - here it's the same version of the one that works, but the agent doesn't wait for the beep and start talking instantly: https://jtuyprjjgxbgmtjiykoa.supabase.co/storage/v1/object/public/recordings/8609614a-3846-40e8-8233-8b2482f5d50f-1731462503741-a90a41a7-4cd9-401d-84fc-d8c6b951ddf9-mono.wav And here is an example of a successful voicemail: https://airtable.com/appfGiIhljt7rZV7w/tbl3RVsNZa8X9P6uZ/viwvf7vGTZQewOlJP/recolZUfnOFluckbN/fldBFS9rsCu48Wrxd?copyLinkToCellOrRecordOrigin=gridView Notice the difference here between the two voice annoucements. Now people will have all sorts of different voicemails messages so I can't catter for them all, but I wanted to discuss with you at least about how you advise me to tweak the parameters to cater for that specific problematic use case, and if you advise to use a voicemail tool. Do you think it has to do with the advanced parameter of the agent as well, like on Punctuation seconds, or on No punctuation seconds? Currently, these values are very low.

set the firstMessageMode to

assistant-waits-for-user

.

@Shubham Bajaj this is already the case. It does wait for the user to speak first. But then when the voicemail kick in, it still says the first message, then the voicemail message

Then you have to configure your twilio voice mail setting according to nature of voicemail to detect if it's voicemail.

TLDR

You have to play with twilio voice mail options to find the best value for use case.

FYI

There is no size, fits all.

@Shubham Bajaj I get it. Where can I find and exhaustive list of all the voicemail detection type ? And why I see in other thread people also adding a voicemail tool? I don’t see any info about this in the documentation. Is it being discontinued?

- No it's being discontinued, we have yet to add the docs for it. - You can create a support ticket to add voice mail detection docs request. - "And why I see in other thread people also adding a voicemail tool? " This means using LLM to check if user input is voicemail using Vapi models. - The info shared with you is the exhaustive list of all the voicemail detection type and config you have to play with it's value and can search more about it on twilio docs.

Thanks man for all the details, I appreciate it 🙂 how long you guys think can add that to the doc? It seems like lots of people would benefit from that as well

By this Sunday,

Thank you!

Yes waiting for your feedback.

@Shubham Bajaj I just tested it. Honestly, I don't see a difference with or without. I feel like it's still mainly in the twilio parameters hand

I guess we are slighlty off from the context, but sitll do let me know your issue.