Interruptions

Interruption handling determines how your agent responds when users speak while the agent is talking. Iqra AI provides multiple strategies—from simple voice activity detection to LLM-based decision making—giving you full control over the conversation dynamics.

Why interruptions matter

Humans naturally interrupt each other in conversation:

Barge-in - “Actually, I need to—”
Backchannel - “Uh-huh”, “mm-hmm”, “I see”
Clarification - “Wait, what was that last part?”
Correction - “No, that’s not my address”

Your agent needs to distinguish between:

Noise (ignore)
Backchannels (acknowledge but keep talking)
Real interruptions (stop and listen)

Configuration overview

Interruption settings live in the agent configuration:

{
  "Interruptions": {
    "UseTurnByTurnMode": false,
    "IncludeInterruptedSpeechInTurnByTurnMode": null,
    "TurnEnd": { /* When to stop listening */ },
    "PauseTrigger": { /* When to pause speaking */ },
    "Verification": { /* Verify if interruption is real */ }
  }
}

Turn-by-turn mode

The simplest approach: strict turn-taking with no interruptions allowed.

UseTurnByTurnMode

boolean

default:"false"

Enable strict turn-taking

true - Agent speaks, waits for silence, then listens
false - Users can interrupt mid-speech (barge-in enabled)

IncludeInterruptedSpeechInTurnByTurnMode

boolean

default:"null"

When agent is interrupted, include what it was saying in context

true - AI knows what was cut off
false - AI only sees what was actually spoken
null - Use system default

When to use:

Formal interactions (legal disclosures, compliance scripts)
Noisy environments where false interruptions are common
Simple IVR-style menus

Example:

Agent: "Your account balance is $1,250. Your last transaction was..."
[User tries to speak - ignored]
Agent: "...a debit of $45 on March 3rd. Do you have any questions?"
[Now user can speak]

Turn end detection

Determines when the user has finished speaking so the agent can respond.

VAD (Voice Activity Detection)

Type: VAD Uses signal processing to detect speech vs. silence.

VadSpeechDurationMS

integer

default:"150"

Minimum milliseconds of speech to register as “user started talking”

VadSilenceDurationMS

integer

default:"300"

Milliseconds of silence to register as “user finished talking”

Configuration example:

{
  "Type": "VAD",
  "VadSpeechDurationMS": 150,
  "VadSilenceDurationMS": 300
}

Pros:

Fastest response time (no API calls)
Deterministic and predictable
Works offline

Cons:

May cut off slow speakers
Can’t distinguish between pause and completion
Sensitive to noise

Increase VadSilenceDurationMS to 500-700ms for elderly users or non-native speakers who pause mid-sentence.

STT (Speech-to-Text)

Type: STT Uses your STT provider’s endpointing logic. Configuration example:

{
  "Type": "STT"
}

Pros:

More accurate than VAD
Provider-optimized algorithms
Language-aware

Cons:

Slightly slower than VAD
Depends on provider quality
Requires network round-trip

When to use: Default for most conversational agents.

ML (Machine Learning)

Type: ML Uses a specialized ML model trained to predict turn completion.

MLTurnEndVADMinimumSpeechDurationMS

integer

default:"150"

Minimum speech duration before ML model activates

MLTurnEndVADMinimumSilenceDurationMS

integer

default:"300"

Minimum silence before ML model evaluates

MlTurnEndFallbackMs

integer

default:"2000"

Maximum wait time before forcing turn end

Configuration example:

{
  "Type": "ML",
  "MLTurnEndVADMinimumSpeechDurationMS": 150,
  "MLTurnEndVADMinimumSilenceDurationMS": 300,
  "MlTurnEndFallbackMs": 2000
}

Pros:

Best at distinguishing pauses from completion
Adapts to speaking patterns
Reduces false triggers

Cons:

Adds latency (model inference time)
Requires ML infrastructure
May need tuning per language

When to use: Complex conversations where users speak in long, multi-clause sentences.

AI (LLM-based)

Type: AI Uses an LLM to analyze if the user’s statement is complete.

UseAgentLLM

boolean

default:"null"

true - Use the agent’s configured LLM
false - Use dedicated LLM (specify in LLMIntegration)

LLMIntegration

object

Custom LLM configuration (if UseAgentLLM: false)

Configuration example:

{
  "Type": "AI",
  "UseAgentLLM": true
}

Pros:

Semantic understanding of completion
Best for complex, multi-turn exchanges
Context-aware decisions

Cons:

Highest latency (LLM API call)
Non-deterministic
Higher cost

When to use: High-value conversations where perfect turn-taking is critical (therapy bots, executive assistants).

AI turn end detection adds 200-500ms latency. Only use when semantic accuracy justifies the delay.

Pause trigger

Determines when to pause the agent’s speech if the user starts talking (barge-in detection).

PauseTrigger.Enabled

boolean

default:"null"

Enable pause trigger (null = disabled)

PauseTrigger.Type

enum

VAD - Voice activity detection
STT - Speech-to-text based

VAD pause trigger

VadDurationMS

integer

Milliseconds of speech detected to trigger pause

Configuration example:

{
  "PauseTrigger": {
    "Type": "VAD",
    "VadDurationMS": 300
  }
}

Behavior:

Agent: "Your account balance is $1,250 and your last trans—"
[User speaks for 300ms]
Agent: [pauses immediately]

STT pause trigger

WordCount

integer

Number of words transcribed to trigger pause

Configuration example:

{
  "PauseTrigger": {
    "Type": "STT",
    "WordCount": 2
  }
}

Behavior:

Agent: "Your account balance is $1,250 and your last trans—"
User: "Wait, stop" [2 words detected]
Agent: [pauses]

Comparison:

Type	Latency	Accuracy	Use Case
VAD	300ms	Moderate	Fast-paced conversations
STT	500-800ms	High	Avoid false positives from noise

Use STT pause trigger with WordCount: 2 to ignore backchannels like “uh-huh” while catching real interruptions.

Interruption verification

After pausing, verify if the interruption was intentional or just noise/backchanneling.

Verification.Enabled

boolean

default:"false"

Enable LLM-based verification

Verification.UseAgentLLM

boolean

default:"true"

true - Use agent’s LLM
false - Use dedicated LLM (specify in LLMIntegration)

Verification.LLMIntegration

object

Custom LLM configuration (if UseAgentLLM: false)

Configuration example:

{
  "Verification": {
    "Enabled": true,
    "UseAgentLLM": true
  }
}

Behavior:

Agent: "Your balance is $1,250 and your last—"
User: "Uh-huh" [pause triggered]
  ↓
LLM analyzes: Is this a real interruption or backchannel?
  ↓
Decision: Backchannel
  ↓
Agent: [resumes] "—transaction was a debit of $45."

vs.

Agent: "Your balance is $1,250 and your last—"
User: "Wait, that's wrong!" [pause triggered]
  ↓
LLM analyzes: Is this a real interruption or backchannel?
  ↓
Decision: Real interruption
  ↓
Agent: [stops completely] "I'm sorry, what was wrong?"

Prompting: The LLM receives:

Agent was saying: "Your balance is $1,250 and your last transaction..."
User said: "Uh-huh"

Is this:
A) A backchannel acknowledgment (agent should continue)
B) A real interruption (agent should stop and respond)

Verification adds ~300ms latency but dramatically improves conversation naturalness by preventing false interruptions.

Configuration strategies

Strategy 1: Fast and simple

Use case: High-volume IVR, simple transactions

{
  "UseTurnByTurnMode": true,
  "TurnEnd": {
    "Type": "VAD",
    "VadSpeechDurationMS": 150,
    "VadSilenceDurationMS": 300
  }
}

Characteristics:

No barge-in
Fastest response time
Deterministic behavior

Strategy 2: Natural conversations

Use case: Customer service, general assistants

{
  "UseTurnByTurnMode": false,
  "TurnEnd": {
    "Type": "STT"
  },
  "PauseTrigger": {
    "Type": "STT",
    "WordCount": 2
  },
  "Verification": {
    "Enabled": true,
    "UseAgentLLM": true
  }
}

Characteristics:

Barge-in enabled
Distinguishes backchannels from interruptions
Balanced latency and accuracy

Strategy 3: Maximum accuracy

Use case: Therapy, coaching, high-stakes consultations

{
  "UseTurnByTurnMode": false,
  "TurnEnd": {
    "Type": "AI",
    "UseAgentLLM": true
  },
  "PauseTrigger": {
    "Type": "STT",
    "WordCount": 3
  },
  "Verification": {
    "Enabled": true,
    "UseAgentLLM": false,
    "LLMIntegration": {
      "provider": "anthropic",
      "model": "claude-3-opus"
    }
  }
}

Characteristics:

Semantic understanding at all stages
Highest accuracy
Higher latency and cost (justified for high-value use cases)

Strategy 4: Noisy environments

Use case: Call centers, outdoor applications

{
  "UseTurnByTurnMode": false,
  "TurnEnd": {
    "Type": "VAD",
    "VadSpeechDurationMS": 200,
    "VadSilenceDurationMS": 500
  },
  "PauseTrigger": {
    "Type": "STT",
    "WordCount": 4
  },
  "Verification": {
    "Enabled": true,
    "UseAgentLLM": true
  }
}

Characteristics:

Higher thresholds to avoid false positives
STT + verification reduce noise interruptions
Slightly slower but more reliable

Testing interruptions

Test backchannels

While agent is speaking, say short acknowledgments:

“Okay”
“Mm-hmm”
“I see”

Agent should continue (if verification enabled).

Test real interruptions

While agent is speaking, say:

“Wait, stop”
“That’s wrong”
“I have a question”

Agent should stop and respond.

Test slow speakers

Pause mid-sentence for 1-2 seconds.Agent should wait (not cut you off).

Test noisy environment

Play background noise or music.Agent should not treat noise as speech.

Test turn-by-turn

Try interrupting in turn-by-turn mode.Agent should ignore interruptions until finished.

Best practices

Match culture and context

Western cultures - More interruptions expected, enable barge-in
Eastern cultures - More respectful turn-taking, consider turn-by-turn mode
Formal contexts - Stricter turn-taking
Casual contexts - More flexible interruptions

Tune for audience

Young adults - Fast VAD thresholds (200ms silence)
Elderly users - Slow VAD thresholds (500-700ms silence)
Non-native speakers - STT or ML turn detection (better at handling pauses)

Provide feedback

When paused, give audio cues:

{
  "AI Response": "[pause tone] Yes, how can I help?"
}

Or use the agent’s personality:

Agent: "Sorry to interrupt—you were saying?"

Monitor false positives

Track metrics:

Interruptions per conversation
Average interruption latency
Backchannel vs. real interruption ratio

Adjust thresholds based on data.

Use dedicated LLMs for verification

For high-traffic agents, use a faster/cheaper model for verification:

{
  "Verification": {
    "Enabled": true,
    "UseAgentLLM": false,
    "LLMIntegration": {
      "provider": "openai",
      "model": "gpt-3.5-turbo"  // Fast and cheap
    }
  }
}

Reserve your primary LLM (e.g., GPT-4) for conversation generation.

Latency breakdown

Configuration	Pause Detection	Turn End Detection	Verification	Total
VAD only	~100ms	~100ms	-	~200ms
VAD + STT	~100ms	~300ms	-	~400ms
STT + Verification	~300ms	~300ms	~300ms	~900ms
ML + Verification	~200ms	~400ms	~300ms	~900ms
AI (full LLM)	~400ms	~500ms	~300ms	~1200ms

Latencies above 500ms are noticeable to users. Only use AI/ML strategies when accuracy justifies the delay.

Next steps

Agent configuration

Complete agent settings reference

Visual IDE

Build conversation scripts

Integrations

Configure LLM and STT providers

Getting Started

Core Concepts

Building Agents

Integrations

Knowledge Base & RAG

Deployment

Channels

Why interruptions matter

Configuration overview

Turn-by-turn mode

Turn end detection

VAD (Voice Activity Detection)

STT (Speech-to-Text)

ML (Machine Learning)

AI (LLM-based)

Pause trigger

VAD pause trigger

STT pause trigger

Interruption verification

Configuration strategies

Strategy 1: Fast and simple

Strategy 2: Natural conversations

Strategy 3: Maximum accuracy

Strategy 4: Noisy environments

Testing interruptions

Best practices

Match culture and context

Tune for audience

Provide feedback

Monitor false positives

Use dedicated LLMs for verification

Latency breakdown

Next steps

Agent configuration

Visual IDE

Integrations

Build docs developers (and LLMs) love

Getting Started

Core Concepts

Building Agents

Integrations

Knowledge Base & RAG

Deployment

Channels

​Why interruptions matter

​Configuration overview

​Turn-by-turn mode

​Turn end detection

​VAD (Voice Activity Detection)

​STT (Speech-to-Text)

​ML (Machine Learning)

​AI (LLM-based)

​Pause trigger

​VAD pause trigger

​STT pause trigger

​Interruption verification

​Configuration strategies

​Strategy 1: Fast and simple

​Strategy 2: Natural conversations

​Strategy 3: Maximum accuracy

​Strategy 4: Noisy environments

​Testing interruptions

​Best practices

​Match culture and context

​Tune for audience

​Provide feedback

​Monitor false positives

​Use dedicated LLMs for verification

​Latency breakdown

​Next steps

Agent configuration

Visual IDE

Integrations

Build docs developers (and LLMs) love

Why interruptions matter

Configuration overview

Turn-by-turn mode

Turn end detection

VAD (Voice Activity Detection)

STT (Speech-to-Text)

ML (Machine Learning)

AI (LLM-based)

Pause trigger

VAD pause trigger

STT pause trigger

Interruption verification

Configuration strategies

Strategy 1: Fast and simple

Strategy 2: Natural conversations

Strategy 3: Maximum accuracy

Strategy 4: Noisy environments

Testing interruptions

Best practices

Match culture and context

Tune for audience

Provide feedback

Monitor false positives

Use dedicated LLMs for verification

Latency breakdown

Next steps