Patent ID: 8452019
Filing Date: 2013-05-28
Classification: H04R

Abstract:
1. A method performed by a testing system for testing a sound processing system (SPS) including first and second microphones, and including a selectable directional filter stage configured to receive an acoustic signal from the microphones, and having at least two directional filters, each configured to provide a corresponding noise cancellation mode with a null at a null axis defined by beamforming, the null axis being at a predetermined direction relative to the axis of the microphones, where a speaker direction is defined to be at zero degrees closest to the first microphone, the method comprising: producing an acoustic signal along a selected first null axis corresponding to a first noise cancellation mode; deactivating the noise cancellation modes; detecting in the selectable directional filter stage an omni-directional output signal in response to the acoustic signal; activating a first noise cancellation mode in the selectable directional filter stage corresponding to a first null at a first null axis; detecting in the selectable directional filter stage a first null signal in response to the acoustic signal corresponding to the first noise cancellation mode; and comparing an amplitude of the first null signal with an amplitude of the omni-directional output signal; such that the SPS is designated as a failing device if the amplitude of the first null signal is not less than the amplitude of the omni-directional output signal by a first predetermined level.