SIP Caller | Voicemail Detection

01

What happens when a call is answered

Call answered

Your campaign reaches a contact

SIP Caller analyzes the answer

Real-time speech analysis

Human

Transfer to your agents, or run any callflow

Standard & AI-Based

Voicemail

Leave a message on the voicemail

Standard & AI-Based

Company IVR

The call is ended and the IVR message is saved in reports, so you can tell your AI agent which DTMF key to press

AI-Based only

Call screener

Introduce the caller, state the purpose, and answer DTMF prompts

AI-Based only

02

Two detection modes

Standard Voicemail Detection

Fast and cost-effective

Our Standard Voicemail Detection performs real-time speech analysis using a sophisticated mathematical algorithm that distinguishes human speech from machine tones with remarkable speed and efficiency, all without any understanding of what is actually being said.

By precisely measuring the duration of the initial salutation, SIP Caller determines the answer type. Long greetings are characteristic of voicemail systems, while short phrases indicate a live person. When a beep tone is detected, the system immediately recognizes an answering machine and triggers the appropriate callflow.

Real-time speech analysis with no noticeable latency
Measures salutation length to detect voicemail greetings
Instant beep tone detection for voicemail systems
No AI cost, runs entirely on SIP Caller infrastructure

AI-Based Voicemail Detection

Maximum accuracy and intelligence

The AI-Based Voicemail Detection streams call audio in real time to an AI agent that truly understands what is being said. This delivers significantly higher accuracy and unlocks powerful new capabilities that go far beyond simple voice analysis.

Because the AI agent comprehends the spoken content, it can separately identify a live human, a company IVR (Interactive Voice Response), and a voicemail system. Humans and voicemail each get their own callflow, while IVR calls are ended and their message is saved in reports, so you can tell the AI agent which DTMF key to press next time. It even handles automated call screeners: the AI can introduce the caller by name, state the purpose of the call, and respond to any DTMF prompts the screener requires.

Higher accuracy than algorithm-based detection
Identifies humans, voicemail systems, and company IVRs separately
Execute a different callflow for humans and voicemail
Bypasses automated call screeners intelligently
Provides the caller name and call purpose to screeners
Responds to DTMF prompts requested by call screeners

03

Which mode is right for you?

Both modes integrate seamlessly into your campaigns. You can choose the best fit based on your accuracy requirements and budget.

Answer types

Standard: Detects humans and voicemail

AI-Based: Distinguishes human, IVR, and voicemail separately

Call screeners

Standard: Not available

AI-Based: Handles automated call screeners

Accuracy

Standard: Works well for most use cases

AI-Based: Higher accuracy than algorithm-based detection

Cost

Standard: Algorithm-based, no AI cost

AI-Based: AI cost paid directly to Gemini, Grok, or OpenAI

Best for

Standard: Great for high-volume campaigns

AI-Based: Ideal for compliance-sensitive campaigns

	Standard Fast and cost-effective	AI-Based Maximum accuracy and intelligence
Answer types	Detects humans and voicemail	Distinguishes human, IVR, and voicemail separately
Call screeners	Not available	Handles automated call screeners
Accuracy	Works well for most use cases	Higher accuracy than algorithm-based detection
Cost	Algorithm-based, no AI cost	AI cost paid directly to Gemini, Grok, or OpenAI
Best for	Great for high-volume campaigns	Ideal for compliance-sensitive campaigns

04

Powered by Gemini, Grok, and OpenAI

SIP Caller integrates with Google Gemini, Grok, and OpenAI as the AI engines for AI-Based Voicemail Detection. You connect your own account with any of these providers directly, so AI consumption is billed straight to you. No markup, no intermediary.