The high directivity of Link•it is obtained by using an array of 3 directional microphones. The main beam is formed by the use of a fixed-sum beamforming endfire array technique. The advantages of fixed beamforming techniques are microphone stability and optimum suppression of diffuse background noise.
The microphones are placed in a straight line. A sound wave coming from the front will have a different arrival time at each microphone than sounds coming from the sides and rear. Each microphone signal is delayed relative to the adjacent one. The microphone signals are then summed, resulting in a high output signal (fig 1). A sound wave coming from the side arrives simultaneously at each microphone, but each microphone signal is delayed differently, resulting in a low output signal (fig 2).
