e whether this is a transcription issue or caller behavior issue.

### Answer The behavior you're describing—where the agent greets but doesn't hear the caller, then triggers reminder messages before hanging up—could be related to several agent configuration settings: Silence Detection & Call Ending: Your agent has an

end_call_after_silence_ms

setting that ends the call if users stay silent after agent speech [(1) ]() [(2) ]() [(3) ]() . The default is 600000 ms (10 minutes) , with a minimum of 10000 ms (10 seconds) . Reminder Configuration: The agent uses

reminder_trigger_ms

to trigger reminders when users are silent after agent speech . The default is 10000 ms (10 seconds) . The

reminder_max_count

controls how many times the agent reminds unresponsive users—default is 1 reminder, and setting it to 0 disables reminders . Potential Audio Issues: If callers' voices aren't being captured, check: -

language

setting matches your callers' language/dialect -

boosted_keywords

may help if specific terms aren't being transcribed -

stt_mode

determines speech-to-text focus on latency vs accuracy (default is "fast") [(2) ]() [(3) ]() Cost Management: To reduce costs from these problematic calls, consider adjusting

max_call_duration_ms

(default 3600000 ms / 1 hour, minimum 60000 ms) [(1) ]() [(2) ]() [(3) ]() or lowering

end_call_after_silence_ms

to end unresponsive calls faster . I'd recommend reviewing your agent's audio configuration and silence/reminder settings to diagnos

​ To learn more, see the sources I considered: [[1] Get Voice Agent](https://docs.retellai.com/api-references/get-agent) [[2] Update Voice Agent](https://docs.retellai.com/api-references/update-agent) [[3] Get Agent Versions](https://docs.retellai.com/api-references/get-agent-versions) ​

Feel free to tag @AI Evy with additional questions. I also appreciate feedback, it helps me improve.

### Answer I understand the cost concern. While you wait for support, here are immediate steps to reduce costs from these problematic calls: Immediate Cost Mitigation: 1. Reduce call duration limits - Set

max_call_duration_ms

to a lower value. The minimum allowed is 60,000 ms (1 min) , with a default of 3,600,000 ms (1 hour) [(1) ]() [(2) ]() . Lowering this will force-end calls faster. 2. Shorten silence timeout - Lower

end_call_after_silence_ms

significantly. The minimum is 10,000 ms (10 s) , with a default of 600,000 ms (10 min) . Setting this to the minimum will end unresponsive calls after just 10 seconds. 3. Reduce reminder attempts - Set

reminder_max_count

to 0 to disable agent reminders entirely, or keep it at 1 (default) . This prevents the agent from repeatedly trying to engage silent callers. Spam Protection Strategies: If these are spam/robocalls, you can implement protective measures [(3) ]() : - Inbound webhook filtering - Enable an inbound webhook on your number, check the

from_number

, and reject suspicious calls by responding with a 200 status without including

override_agent_id

- Agent-level detection - Add logic in your agent's prompt to detect repeated or bot-like audio patterns and instruct the agent to hang up quickly - Rate limiting - Implement rate limits by phone number or IP address These configuration changes can be made immediately via the API or dashboard to stop the cost accumulation while support investigates the root cause.

​ To learn more, see the sources I considered: [[1] Get Voice Agent](https://docs.retellai.com/api-references/get-agent) [[2] Update Voice Agent](https://docs.retellai.com/api-references/update-agent) [[3] Request for Fee Waiver Due to Spam Calls on Voice Agent](https://community.retellai.com/t/request-for-fee-waiver-due-to-spam-calls-on-voice-agent/371) ​

Feel free to tag @AI Evy with additional questions. I also appreciate feedback, it helps me improve.