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Call falsely identified as Voicemail
# support
m
CallId: 40a564d2-3c5f-4069-bd4d-4d1db4168a70 When running an outbound campaign, we got 20% of 40 calls wrongly identified as voicemail whereas they were real human conversations. We currently use google provider for voicemail detection with the following config:
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assistant.voicemailDetection = {
      provider: "google",
      voicemailExpectedDurationSeconds: 15,
    }
Should we update this config?
v
Hi there! 👋 I don't have specific information about optimizing the 
voicemailExpectedDurationSeconds
parameter for Google's provider. However, I can definitely help with alternative approaches to improve your voicemail detection accuracy. Based on the information I found, you have several options to reduce those false positives: ## Alternative Providers You might want to consider switching from Google to one of these alternatives: 1. **Twilio**: Many users have found success with Twilio's voicemail detection. According to [Vapi's documentation](https://docs.vapi.ai/phone-calling/voice-mail-detection), you can configure it like this:
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json
   {
     "voicemailDetection": {
       "provider": "twilio",
       "enabled": true,
       "machineDetectionTimeout": 30,
       "machineDetectionSpeechThreshold": 2400,
       "machineDetectionSpeechEndThreshold": 1200,
       "machineDetectionSilenceTimeout": 5000,
       "voicemailDetectionTypes": [
         "machine_end_beep",
         "machine_end_silence",
         "machine_end_other"
       ]
     }
   }
2. **Vapi's Built-in Tool**: [Vapi documentation](https://docs.vapi.ai/phone-calling/voice-mail-detection) shows you can use their LLM-powered voicemail detection tool:
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json
   {
     "model": {
       "tools": [{ "type": "voicemail" }]
     }
   }
3. **Combined Approach**: For best results, [Vapi's documentation](https://docs.vapi.ai/phone-calling/voice-mail-detection) suggests you can use both Twilio and Vapi's tool together:
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json
   {
     "voicemailDetection": {
       "provider": "twilio",
       "voicemailDetectionTypes": [
         "machine_start",
         "machine_end_beep",
         "unknown"
       ],
       "enabled": true,
       "machineDetectionTimeout": 15
     },
     "model": {
       "tools": [{ "type": "voicemail" }]
     }
   }
## Improving Detection Accuracy
According to information from [Discord conversations](https://discord.com/channels/1211482211119796234/1211483291191083018/threads/1342555558984814653), longer timeouts (like 30 seconds instead of 15) can be more reliable for voicemail detection and prevent legitimate calls from being cut off. Also, when configuring 
voicemailDetectionTypes
, it's suggested to use "unknown" instead of "human" to avoid false positives, based on [user experiences shared in Discord](https://discord.com/channels/1211482211119796234/1211483291191083018/threads/1305065394662408192). Would you like me to provide more details on any of these options? Sources: - [Vapi's documentation on voicemail detection](https://docs.vapi.ai/phone-calling/voice-mail-detection) - [Discord conversation about voicemail detection timeouts](https://discord.com/channels/1211482211119796234/1211483291191083018/threads/1342555558984814653) - [Discord conversation about voicemail detection types](https://discord.com/channels/1211482211119796234/1211483291191083018/threads/1305065394662408192)
s
Hey Marem, give me some time to check how it's going for others using the same language as you are using for detecting voicemails using Google. If it wasn't working for them, what did they pivot to?
Hey Marem, I tried looking into other configs, but the solution which you can potentially try out is increasing the voicemail expected duration seconds. You can go up to a maximum of 60 seconds. Give it a try with different values and let me know what works for you.
m
yes, ok. I increased it from 15s to 30s for now.
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