File size: 2,297 Bytes
1919bbe | 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 | """
===============================================================================
preprocessing/noise_reduction.py — Spectral Noise Reduction
===============================================================================
"""
import numpy as np
import noisereduce as nr
from config import NOISE_PROFILE_DURATION, TARGET_SR
def reduce_noise(audio, sr):
"""
Apply spectral noise reduction to the audio signal.
Estimates the noise profile from the first NOISE_PROFILE_DURATION seconds
of the recording, then uses spectral subtraction to remove stationary noise.
Parameters
----------
audio : np.ndarray
1D array of audio samples (already resampled to TARGET_SR).
sr : int
Sampling rate of the audio.
Returns
-------
np.ndarray
Denoised audio signal, same length as input.
Notes
-----
- `prop_decrease`: How much to reduce the noise (0.0 = no reduction,
1.0 = full removal). Start with 0.8 and tune based on results.
- If the noise profile segment is too short (< 0.1s), fall back to
using the entire clip for noise estimation with a lower prop_decrease.
"""
# Calculate how many samples correspond to the noise profile duration
noise_samples = int(sr * NOISE_PROFILE_DURATION)
# --- Estimate noise profile ---
if len(audio) > noise_samples and noise_samples > int(sr * 0.1):
# Use the first N seconds as the noise reference
noise_clip = audio[:noise_samples]
prop_decrease = 0.8 # Moderate reduction
else:
# Fallback: use the whole clip (less accurate, so be conservative)
noise_clip = audio
prop_decrease = 0.5 # Conservative reduction
# --- Apply spectral noise reduction ---
# TODO (EL sir): Implement the actual noise reduction call.
cleaned = nr.reduce_noise( y = audio,
sr = sr,
y_noise = noise_clip,
prop_decrease = prop_decrease
) # PLACEHOLDER — replace with actual implementation
return np.clip(cleaned, -1.0, 1.0) # the reason I used clip is that the noise reduction can produce some artifacts
# that are louder than the original audio so it can be consistant with the norml]alization I made
|