Prepare labelled audio
Collect speech recordings with quality labels (MOS, accept/reject) and split by speaker and recording conditions to avoid leakage.
Analyse speech prosody. Assess quality-related cues.
Prosody analysis measures pitch, energy, timing and spectral cues that correlate with perceived speech quality. Practical work requires robust feature extraction from real recordings, a clear target variable (e.g. MOS or binary acceptability) and evaluation that reflects real decisions such as perceptual correlation and latency constraints.
Learning concept · Not a validated service
Prosody analysis measures pitch, energy, timing and spectral cues that correlate with perceived speech quality. Practical work requires robust feature extraction from real recordings, a clear target variable (e.g. MOS or binary acceptability) and evaluation that reflects real decisions such as perceptual correlation and latency constraints.
A proposed product: monitor telephony or contact-centre audio quality and flag segments with degraded prosody features for human review. Any deployment should keep human reviewers in the loop and not rely solely on automated scores for customer-facing actions.
Collect speech recordings with quality labels (MOS, accept/reject) and split by speaker and recording conditions to avoid leakage.
Compute pitch (F0), voicing, energy, durations and pause statistics with a library such as librosa or parselmouth; aggregate over segments.
Fit a simple regressor or classifier (random forest or small NN) on the extracted features and keep the pipeline reproducible.
Report correlation or macro F1 depending on the label type, inspect low-confidence examples and measure noise/codec sensitivity.
The supplied starter synthesises pure-tone clips, computes a simple FFT-based spectral summary (mean, std, argmax, 95th percentile), creates two synthetic classes by frequency (around 440Hz and 880Hz), and fits a RandomForest classifier to distinguish them. It does not process real speech, compute classic prosodic features (pitch, energy, pauses) or predict speech-quality labels.
def synth_clip(freq, label):
t = np.linspace(0, 1, sample_rate, endpoint=False)
signal = np.sin(2 * np.pi * freq * t) + 0.05 * rng.normal(size=sample_rate)
spectrum = np.abs(np.fft.rfft(signal))
features = [
spectrum.mean(),
spectrum.std(),
spectrum.argmax(),
np.percentile(spectrum, 95),
]The starter uses synthetic sine waves with added noise and spectrum summaries as features; these are not speech prosody descriptors and the binary labels correspond only to different sine frequencies, so the code does not validate prosody-based speech-quality analysis on real speech data.
A proposed extension is to replace the synthetic data with real speech labelled for perceived quality (MOS or acceptability), extract frame- and segment-level prosodic features (F0, energy, jitter, shimmer, pause durations) and train a regressor to predict quality scores; surface low-confidence segments for human review.
This is a potential application pathway, not a delivered product. The supplied starter does not implement this service or validate it with real users.
Networkers Home runs this topic inside its AI Engineer Course, with placement support and hands-on labs.