The application discloses a photoacoustic
signal enhancement method and device based on adaptive multi-band
spectral subtraction and Wiener filtering, and belongs to the technical field of speech
signal enhancement. The application divides a
signal into sub-bands according to Mel scale, determines a subtraction factor and a
lower limit factor by a monotone decreasing function linkage according to real-
time signal-to-
noise ratio of each sub-band, and makes the two factors negatively correlated with the signal-to-
noise ratio, so that the denoising strength and the spectral bottom filling depth are automatically adapted; the weighted
moving average of the power spectrum of adjacent sub-bands is carried out to smooth isolated spectral peaks and spectral valleys left by
spectral subtraction; a residual amplitude limiting is introduced before Wiener filtering, the maximum
noise residual threshold is determined based on adjacent frame statistics and limiting, and Wiener filtering is carried out by taking the data after limiting as clean signal
estimation; the
noise spectrum is recursively updated by a
forgetting factor which is dynamically adjusted according to the signal-to-noise ratio, and is only executed in the speech inactive section. The application has an output signal-to-noise ratio improvement of more than 50% when the input is 0dB, can stably enhance without damage under high signal-to-noise ratio, and is suitable for photoacoustic
speech acquisition and enhancement scenes.