Single-channel noise reduction in the STFT domain based on the bifrequency spectrum
Bibliographic record
Abstract
This paper studies the problem of noise reduction in the short-time Fourier transform (STFT) domain. Traditionally, the STFT coefficients in different frequency bands are assumed to be independent. This assumption holds when the signals are stationary and the fast Fourier transform(FFT) length is sufficiently large. In practice, however, speech is nonstationary and also the FFT length cannot be very large due to practical reasons. So, there always exists some correlation between STFT coefficients from neighboring frequency bands. An important question then arises: how the interband correlation can be used to optimize noise reduction performance? This paper addresses this issue. We discuss two solutions in the framework of the bifrequency spectrum. One considers the cross-correlation between all the frequency bands and the other takes into account only the cross-correlation between neighboring bands. While the former is optimal from a theoretical perspective, the latter is more practical as it is more immune to the error in correlation matrix estimation.
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How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.001 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.001 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.001 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.000 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one teacher head, not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".