Reduction of self-noise effects in onboard acoustic receivers of vessels using spectral subtraction

Supriya Menonkattil Hariharan , Suraj Kamal , Saseendran Pillai

The engine noise, the turbulence, cavitation created by the propellers generates severe levels of acoustic noise in the vicinity. The onboard hydrophones of acoustic receivers or other observation systems will essentially pickup these near-filed noise to a greater extent from their immediate surroundings. This will introduce a major challenge in effective listening of signals of interest that are camouflaged by the noise ambience. The paper discusses a method based on spectral subtraction for reducing the effect of these uniform noise field created by engines or propellers in the surroundings of acoustic receivers. Spectral subtraction is a technique used to retrieve the power spectrum of a non-stationary signal of interest in a uniform noise field by subtracting an estimated average of noise spectrum from the originally observed signal spectrum. The noise spectrum is estimated apriori to the actual communication or observation, i.e while the signal of interest is absent or silent. The process will repeat in a cyclical manner, at periodic intervals to adapt with the spectral shifts that may have occurred in the noise field. The method can be used with acoustic receiver front ends as a preconditioning stage for improving the overall signal quality.

Mots clés: Spectral Subtarction; Engine Noise; Turbulence; Cavitation

Domaines: Acoustique [physics.class-ph]

Supriya Menonkattil Hariharan, Suraj Kamal, Saseendran Pillai. Reduction of self-noise effects in onboard acoustic receivers of vessels using spectral subtraction. Acoustics 2012, Apr 2012, Nantes, France. ⟨hal-00811360⟩