METHOD OF MASKING ANALOGUE SPEECH SIGNALS Russian patent published in 2015 - IPC G10L19/00 H04K1/04 

FIELD: radio engineering, communication.

SUBSTANCE: analogue speech signal is sampled with a standard frequency of 8000 Hz. The sampled speech signal is transmitted to the input of a bandpass filter with cut-off bands of 0.3 kHz and 3.4 kHz. Discrete Fourier transform is performed over the filtered signal to obtain expansion coefficients. Further, the expansion coefficients are rearranged in reverse order. Inverse discrete Fourier transform is then performed, after which the spectrum of the speech signal becomes inverted with respect to the initial spectrum. The disclosed transformation is characterised by that the signal becomes inverted on time.

EFFECT: faster transformation.

6 dwg