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Voice Effects

HushCircuits includes a real-time voice modulation engine that transforms your voice as it passes through the bridge. Effects are applied server-side, so the target only hears the modified version.

Effect Modes

VOICE MODULATION ENGINE

Real-time audio transformation via bridge

OFF🎙️

Natural voice passthrough with no processing. Your voice is transmitted as-is through the bridge.

BYPASS
DEEP🔊

Lowers pitch by several semitones. Creates a deeper, more authoritative voice. Effective for basic disguise.

-6 SEMITONES
ROBOT🤖

Synthetic modulation with ring modulation and vocoder effects. Makes voice sound mechanical and non-human.

VOCODER
ANON👻

Full anonymization — combines pitch shift, formant alteration, and spectral masking. Maximum voice privacy.

FULL MASK
DSP ENGINE: STANDBY

Detailed Breakdown

OFF — Natural Passthrough

Your voice is transmitted without any processing. Use this when voice privacy isn't needed, or when you want the clearest possible audio quality.

  • Use case: Calls where you don't need voice disguise
  • Audio quality: Maximum
  • Processing: None (bypass)

DEEP — Pitch Shift

Lowers your voice by several semitones, creating a deeper, more authoritative tone. This is the most subtle effect — it changes your voice enough to prevent casual recognition while still sounding natural.

  • Use case: Basic voice disguise for casual privacy
  • Audio quality: High
  • Processing: Pitch shift via FreeSWITCH mod_soundtouch

ROBOT — Vocoder

Applies ring modulation and vocoder effects to make your voice sound synthetic and mechanical. The result is clearly non-human, making it impossible to identify your natural voice characteristics.

  • Use case: Maximum unrecognizability while remaining intelligible
  • Audio quality: Medium (intentionally distorted)
  • Processing: Ring modulation + vocoder chain

ANON — Full Anonymization

The most aggressive effect. Combines pitch shifting, formant alteration, and spectral masking. Your voice is completely transformed — gender, age, and accent are all obscured.

  • Use case: Highest possible voice privacy
  • Audio quality: Medium-low (heavy processing)
  • Processing: Multi-stage DSP pipeline

How to Use

  1. On the main dialer, find the VOICE row below the CID display
  2. Tap your desired effect: OFF, DEEP, ROBOT, or ANON
  3. The selected effect highlights in cyan
  4. Press DIAL — the effect is applied for the entire call

TIP

You must select the voice effect before pressing DIAL. You cannot change the effect during an active call.

Technical Details

Voice effects are processed by FreeSWITCH mod_soundtouch on the bridge server. The audio pipeline is:

Your Voice → Bridge Server → mod_soundtouch → Target

Since processing happens server-side, there's no additional load on your device and no client-side audio leakage.