Learning
Bits

Speech Enhancement with Sparse Coding in Learned Dictionaries

Christian Sigg, Tomas Dikk and Joachim M. Buhmann

This page provides complementary material for our ICASSP 2010 paper.

Enhanced Speech Examples

The following plots compare our dictionary learning based enhancer with multi-band spectral subtraction and a vector quantization based enhancer (see the paper for details of the algorithms). "Noisy mixture" is the log-magnitude spectrogram of the additive mixture of speech and interferer, and the three other plots show log-magnitude spectrograms after the mixture signal has been enhanced by the respective algorithm. Click on an image to play the example (8kHz WAVE format).

Street Noise at 6 dB SNR

Noisy mixture
Noisy mixture
Spectral subtraction
Multi-band spectral subtraction
Vector quantization
Vector quantization
(speaker independent)
Dictionary learning
Dictionary learning
(speaker independent)

Music over Stereo in Closed Room at 0 dB SNR

Noisy mixture
Noisy mixture
Spectral subtraction
Multi-band spectral subtraction
Vector quantization
Vector quantization
(speaker independent)
Dictionary learning
Dictionary learning
(speaker independent)

Objective Measures

The following graphs compare our dictionary learning based enhancer (speaker dependent: DL_d, and speaker independen: DL_i) with multi-band spectral subtraction (SP) and vector quantization based enhancement (speaker independent: VQ_i), using several objective speech quality measures that have been shown to correlate with subjective speech quality judgement.

Cepstrum Distance

Cepstrum distance improvement at 12 dB SNR
Cepstrum distance improvement at 6 dB SNR
Cepstrum distance improvement at 0 dB SNR

Segmental SNR

Segmental SNR improvement at 12 dB SNR
Segmental SNR improvement at 6 dB SNR
Segmental SNR improvement at 0 dB SNR

Frequency Weighted Segmental SNR

Frequency weighted segmental SNR improvement at 12 dB SNR
Frequency weighted segmental SNR improvement at 6 dB SNR
Frequency weighted segmental SNR improvement at 0 dB SNR

PESQ Measure

PESQ measure at 12 dB SNR
PESQ measure at 6 dB SNR
PESQ measure at 0 dB SNR