Displaying a Spectrogram of a Speech Signal with MATLAB

Resource Overview

Using MATLAB to visualize a speech signal's spectrogram and identify formant characteristics through signal processing techniques

Detailed Documentation

Generate a spectrogram of a speech signal using MATLAB to display acoustic features such as formants. Here's a comprehensive implementation approach:

1. Launch MATLAB and import your speech signal using functions like audioread() for WAV files or audioDeviceReader for real-time acquisition. Preprocess the signal by normalizing amplitude and applying windowing functions.

2. Compute the spectrogram using MATLAB's built-in spectrogram() function, which employs Short-Time Fourier Transform (STFT) to visualize frequency distribution over time. Key parameters include window size (typically 20-30ms for speech), overlap percentage, and FFT length for frequency resolution.

3. Analyze the spectrogram to identify formant patterns (F1, F2, F3) which appear as dark energy bands in the frequency domain. Use peak detection algorithms or MATLAB's findpeaks() function to automatically locate formant frequencies in specific time frames.

4. Visualize the results using MATLAB's plotting functions like imagesc() or spectrogram() with customized colormaps. Enhance clarity by adding frequency labels, time markers, and formant trajectory overlays using plot() or line() functions.

By implementing these steps with proper parameter tuning, you can effectively analyze speech acoustic properties through spectrogram visualization and formant tracking in MATLAB.