Spectral subtraction for stationary noise

1. What is spectral subtraction noise reduction?
2. What is spectral noise reduction?

What is spectral subtraction noise reduction?

The spectral subtraction is historically one of the first algorithms proposed for the enhancement of single channel speech. In this method, the noise spectrum is estimated during speech pauses, and is subtracted from the noisy speech spectrum to estimate the clean speech.

What is spectral noise reduction?

The spectral subtraction method is a simple and effective method of noise reduction. In this method, an average signal spectrum and average noise spectrum are estimated in parts of the recording and subtracted from each other, so that average signal-to-noise ratio (SNR) is improved.