Enhanced Adaptive Pitch Shifter – User Guide
Advanced Praat script with presets, multiple modulation sources, and professional audio processing.
What this does
This enhanced script provides professional-grade adaptive pitch shifting with multiple modulation sources and creative presets. Unlike simple pitch shifting, this script uses Praat's Manipulation object to create dynamic, context-aware pitch transformations.
Version 2.0 Features:
- 6 Creative Presets – Ready-to-use effects from subtle wobble to extreme warping
- 4 Modulation Sources – Amplitude-based, pitch contour, LFO, or combined modulation
- Advanced Controls – Smoothing, formant preservation, stereo width, and quality settings
- Preview Mode – Test effects without creating permanent objects
- Professional Quality – Uses PSOLA and overlap-add resynthesis for clean results
Technical Implementation: This script extracts pitch contours using Praat's pitch detection algorithms, then modifies them using various modulation sources. The modulation can be driven by the signal's amplitude envelope (extracted via Intensity object), the pitch contour itself, a time-based LFO (Low Frequency Oscillator), or a combination. The modified pitch tier is applied to a Manipulation object, which uses either PSOLA (Pitch-Synchronous Overlap-Add) or overlap-add resynthesis to generate the output with minimal artifacts. Formant preservation maintains vocal character by keeping formant frequencies stable while shifting pitch.
Quick start
- In Praat, select a Sound object.
- Run script… →
Enhanced Adaptive Pitch Shifter.praat. - Choose a Preset or set parameters manually.
- Enable Preview only to test without saving.
- Click OK – output plays automatically.
Presets
Six carefully crafted presets provide instant creative effects:
1. Custom
Use manual parameter settings for full control.
2. Subtle Wobble Gentle
Use case: Add organic movement to vocals or instruments without obvious pitch shifting.
Settings: Base 1.0, Modulation 0.15, Amplitude source, 4Hz, Smoothing 0.2
3. Robot Voice Effect
Use case: Mechanical, synthetic vocal effects for creative production.
Settings: Base 0.8, Modulation 0.8, LFO source, 8Hz, Smoothing 0.05
4. Harmonic Shimmer Musical
Use case: Ethereal, floating quality for pads, vocals, or ambient music.
Settings: Base 1.5, Modulation 0.3, Pitch contour source, 2Hz, Smoothing 0.3
5. Deep Bass Mod Low End
Use case: Downshift with dynamic movement for bass enhancement or special effects.
Settings: Base 0.5, Modulation 1.0, Combined source, 1.5Hz, Smoothing 0.15
6. Vibrato Effect Classic
Use case: Natural vibrato or tremolo-like pitch oscillation.
Settings: Base 1.0, Modulation 0.08, LFO source, 5.5Hz, Smoothing 0.4
7. Extreme Warp Experimental
Use case: Dramatic, glitchy effects for sound design and experimental music.
Settings: Base 1.2, Modulation 1.5, Combined source, 10Hz, Smoothing 0.0
Parameters
Basic Controls
| Parameter | Type | Default | Description |
|---|---|---|---|
| Preset | menu | Custom | Select predefined effect or Custom for manual control |
| Base_pitch_shift | positive | 1.0 | Base pitch multiplier (0.5 = octave down, 2.0 = octave up) |
| Modulation_amount | positive | 0.5 | Intensity of pitch modulation effect |
Advanced Controls
| Parameter | Type | Default | Description |
|---|---|---|---|
| Modulation_source | menu | Amplitude | What drives pitch changes (see Modulation Sources below) |
| LFO_frequency | positive | 3.0 | Oscillation speed in Hz (for LFO and Combined modes) |
| Smoothing_factor | positive | 0.1 | Reduces abrupt transitions (0 = none, 1 = maximum) |
Processing Options
| Parameter | Type | Default | Description |
|---|---|---|---|
| Apply_formant_preservation | boolean | Yes | Maintain vocal character (use overlap-add resynthesis) |
| Add_stereo_width | boolean | No | Convert mono to stereo with width enhancement |
| Output_gain | positive | 1.0 | Final volume multiplier |
Quality Settings
| Parameter | Type | Default | Description |
|---|---|---|---|
| Quality | menu | Standard | Fast (quick preview), Standard (balanced), High Quality (best results) |
| Preview_only | boolean | No | Play without creating permanent output object |
Modulation Sources
The modulation source determines what drives the pitch changes:
| Source | How it works | Best for |
|---|---|---|
| Amplitude | Pitch follows signal volume (louder = higher/lower pitch) | Dynamic material, drums, vocals with varied dynamics |
| Pitch Contour | Modulation based on detected pitch (creates harmonic relationships) | Melodic content, sustained tones, vocals |
| Time-based LFO | Sine wave oscillator creates periodic pitch movement | Vibrato, tremolo effects, rhythmic modulation |
| Combined | Mix of amplitude envelope and LFO for complex movement | Experimental effects, sound design, dramatic changes |
Outputs
- Object name: [original_name]_shifted
- Sample rate: Matches input sound
- Channels: Mono (or stereo if Add_stereo_width enabled)
- Normalization: Controlled by Output_gain parameter
- Info window: Displays processing progress and settings used
Note: If Preview_only is enabled, the sound plays but no permanent object is created.
Usage Examples
Example 1: Vocal Enhancement
Preset: Subtle Wobble Modulation_source: Amplitude Apply_formant_preservation: Yes Quality: High Quality
Adds natural, organic movement to flat vocal recordings.
Example 2: Creative Vocal Effect
Preset: Robot Voice Add_stereo_width: Yes Output_gain: 0.8
Creates synthetic, processed vocal effect with stereo enhancement.
Example 3: Ambient Pad Processing
Preset: Harmonic Shimmer Quality: High Quality Preview_only: Yes (test first)
Adds ethereal, floating quality to synthesizer pads.
Example 4: Custom Bass Enhancement
Preset: Custom Base_pitch_shift: 0.7 Modulation_amount: 0.3 Modulation_source: Combined LFO_frequency: 2.0 Smoothing_factor: 0.2
Downshift bass with gentle dynamic movement.