🎤 Voice Atelier — Phase Vocoder Project

OBL - 4101 • Digital Signal Processing • ESIEE Paris

Welcome to Voice Atelier, a complete project implementing a Phase Vocoder and additional audio effects in MATLAB, accompanied by a demo website hosted through GitHub Pages.

🔗 Live Demo Website:
➡️ https://ana-bea-s.github.io/Voice_Atelier/

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🎯 Project Overview

This project is part of the OBL - 4101 Digital Signal Processing course and focuses on the implementation of a Phase Vocoder, capable of producing the following audio effects:

✅ Mandatory Effects

1. Time-stretching Modify the speed of the voice without changing its pitch.
2. Pitch-shifting Modify the pitch of the voice while preserving the duration.
3. Robotisation Apply a ring modulation process to transform the voice into a robotic sound.

These effects rely on:

• Short-Time Fourier Transform (STFT)
• Frequency-domain interpolation
• Phase tracking
• Resampling
• Time-domain modulation

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✨ Additional Custom Effects

Three additional effects were implemented to personalize the project:

🎶 Harmonic Duo / Trio

Generates multiple harmonized voices using pitch shifting.

👻 Whisper / Ghost Voice

Breaks phase coherence to simulate whispered, airy, or spectral voices.

☎️ Telephone / Radio Effect

Simulates communication devices using:

• Band-pass filtering (300–3400 Hz)
• Soft distortion
• Low-level background noise

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🧠 Core MATLAB Functions

File	Description
PVoc.m	Main phase vocoder (STFT → interpolation → iSTFT)
TFCT.m	Short-Time Fourier Transform
TFCTInv.m	Inverse STFT
TFCT_Interp.m	Frequency-domain interpolation
Rob.m	Ring modulation for robotisation
Vocodeur.m	Main interactive menu and audio processing controller
HarmonicDuoTrio.m	Additional effect 1
WhisperGhostVoice.m	Additional effect 2
TelephoneRadioEffect.m	Additional effect 3

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▶️ Running the Project

Requirements

• MATLAB
• Signal Processing Toolbox (for resample)

Steps

1. Open MATLAB
2. Navigate to the MATLAB folder:

   cd('MATLAB')

3. Run the main program:

   Vocodeur

4. Select an audio file
5. Choose an effect from the menu and listen to the result

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🌐 Website Demo

A small interactive website is included to visually present the project.

🔗 https://ana-bea-s.github.io/Voice_Atelier/

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👥 Authors

Ana Beatriz Santos de Oliveira

Larissa Anielle Terrinha de Oliveira

OBL - 4101 • Digital Signal Processing

ESIEE Paris

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📄 License

This repository is part of an academic project and intended for educational use.