Audio Devices

Configure system audio and microphone capture for real-time transcription.

Overview

Intervu captures two audio sources simultaneously:

Source	Purpose	Speaker Label
System Audio	Interviewer's voice (from video calls)	"Interviewer"
Microphone	Your voice	"You"

Virtual Audio Required

System audio capture requires a virtual audio device:

• Windows: VB-Cable — See Prerequisites
• macOS: BlackHole — See macOS Setup

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Windows Setup

System Audio Device (VB-Cable)

This captures the interviewer's voice from video calls (Zoom, Teams, Meet, etc.).

How to set up:

1. Install VB-Cable (see Prerequisites)
2. In your video call app, set Speaker Output to CABLE Input
3. In Intervu Settings, select CABLE Output as System Audio Device

┌─────────────┐     ┌──────────────┐     ┌─────────────┐
│ Video Call  │────▶│ CABLE Input  │────▶│ CABLE Output│
│ (Speaker)   │     │ (VB-Cable)   │     │ (Intervu)   │
└─────────────┘     └──────────────┘     └─────────────┘

You Can't Hear Audio Through VB-Cable Alone

When you route system audio to VB-Cable, you won't hear the interviewer. The audio goes to Intervu but not to your speakers. To fix this, use an audio routing solution:

Option 1: SteelSeries GG (steelseries.com/gg)

• Install SteelSeries GG (free, not just for SteelSeries hardware)
• Set up audio mirroring to send audio to both your speakers and VB-Cable
• Simplest option for most users

Option 2: Voicemeeter (vb-audio.com/Voicemeeter)

• Install Voicemeeter (free)
• Set Voicemeeter as your default audio device
• Route audio to both your speakers (A1) and VB-Cable (A2)
• More powerful but steeper learning curve

Recommended: VB-Cable + Audio Router (You Can Hear Audio)

┌─────────────┐     ┌──────────────────┐     ┌──────────────┐     ┌─────────────┐
│ Video Call   │────▶│ SteelSeries GG / │────▶│ CABLE Input  │────▶│ Intervu     │
│ (Speaker)   │     │ Voicemeeter      │     │ (VB-Cable)   │     │ (Capture)   │
└─────────────┘     └──────┬───────────┘     └──────────────┘     └─────────────┘
                           │
                           ▼
                    ┌──────────────┐
                    │ Speakers /   │
                    │ Headphones  │
                    │ (You Hear)  │
                    └──────────────┘

Microphone Device

Select your physical microphone or headset.

1. In Intervu Settings, click the Microphone dropdown
2. Select your microphone device
3. The audio level meter shows real-time input

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macOS Setup

System Audio Device (BlackHole)

On macOS, use BlackHole to capture system audio, combined with a multi-output device so you can still hear the audio.

How to set up:

1. Install BlackHole from existential.audio
2. Open Audio MIDI Setup → Click + → Create Multi-Output Device
3. Check BlackHole 2ch and your speakers/headphones
4. Rename to "Intervu Multi-Output"
5. Open System Settings → Sound → Output
6. Select "Intervu Multi-Output"
7. In Intervu Settings, select BlackHole 2ch as System Audio Device

┌─────────────┐     ┌──────────────────────┐     ┌──────────────┐     ┌─────────────┐
│ Video Call   │────▶│ Multi-Output Device  │────▶│ BlackHole    │────▶│ Intervu     │
│ (System Out) │     │ (Audio MIDI Setup)   │────▶│ (System Audio│     │ (STT + LLM) │
└─────────────┘     └──────────────────────┘     │  Capture)    │     └─────────────┘
                              │                    └──────────────┘
                              ▼
                    ┌──────────────┐
                    │ Speakers /   │
                    │ Headphones   │
                    │ (You Hear)   │
                    └──────────────┘

For detailed macOS instructions, see macOS Setup Guide.

Why Multi-Output Device?

Without a multi-output device, BlackHole captures audio but you can't hear it. The multi-output device sends audio to both your speakers (so you hear the interviewer) and BlackHole (so Intervu captures it). This is the macOS equivalent of using VB-Cable + SteelSeries GG/Voicemeeter on Windows.

Microphone Device

1. In Intervu Settings, click the Microphone dropdown
2. Select your microphone device
3. The audio level meter shows real-time input
4. If no devices appear, grant microphone permission in System Settings → Privacy & Security → Microphone

Microphone Permission Required

macOS requires explicit microphone permission. When you first click the microphone button, macOS will prompt for access. If you miss the prompt, go to System Settings → Privacy & Security → Microphone and enable Intervu.

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Audio Level Meters

Intervu displays real-time audio levels in the title bar:

• System: Blue meter — interviewer's audio level
• Mic: Green meter — your audio level

Level Indicators

Level	Meaning
Filled	Audio is being captured
Empty	No audio or silent
Red peak	Audio clipping (too loud)

Best Practices

• Keep levels in the green/yellow range
• Avoid red peaks (distortion)
• Adjust system volume if needed

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Refreshing Devices

If devices don't appear:

Windows

1. Click Refresh Devices in Settings
2. Ensure VB-Cable is installed and visible in Windows Sound Settings
3. Restart the application if devices still don't appear

macOS

1. Click Refresh Devices in Settings
2. Ensure BlackHole is installed and FFmpeg is available (brew install ffmpeg)
3. Grant microphone permission in System Settings → Privacy & Security → Microphone
4. Restart the application if devices still don't appear

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Troubleshooting

No devices listed

See No Audio Devices or macOS Troubleshooting.

Audio is too quiet

Windows:

1. Increase system volume
2. Check Windows Sound Settings → Recording → Properties → Levels
3. Adjust microphone boost if available

macOS:

1. Increase system volume
2. Check Input Volume in System Settings → Sound → Input
3. Try an external microphone if the built-in one is too quiet

Audio is clipping (distorted)

1. Decrease system volume
2. Check for microphone boost and reduce it
3. Move microphone further from mouth

Can't hear the interviewer

Windows: VB-Cable alone routes audio away from your speakers. Use SteelSeries GG or Voicemeeter to route audio to both VB-Cable and your speakers.

macOS: Create a multi-output device in Audio MIDI Setup that includes both BlackHole and your speakers. See macOS Setup Guide for detailed instructions.

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Platform Differences

Feature	Windows	macOS
Virtual Audio	VB-Cable	BlackHole
Audio Routing	SteelSeries GG / Voicemeeter	Multi-Output Device (Audio MIDI)
FFmpeg	Bundled	Manual (brew install ffmpeg)
Audio API	DirectShow	AVFoundation
Microphone Perm	Windows Settings	System Settings → Privacy

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Related Settings

• STT Endpoint — Configure transcription
• Advanced Settings — Configure silence threshold
• macOS Setup — Detailed macOS audio setup