Processing echoes received at a directional microphone unit

A method of using a directional microphone unit, the directional microphone unit comprising an array of constituent microphones spaced apart from one another, and the method comprising:

• at each respective one of a plurality of the microphones, receiving substantially white noise via a direct path from a source of the white noise and also receiving an echo comprising a reflection of the white noise from at least one reflective surface, and thereby obtaining a received noise signal comprising a combination of the directly-received noise and the echo as received by the respective microphone;
• for each of the plurality of microphones, identifying a spacing between lobes and/or troughs in a respective spectrum of the received noise signal as received by the respective microphone, thereby determining an additional distance travelled by the echo to the respective microphone relative to the direct path;
• calculating a direction of the source based on the additional distance travelled for each of said plurality of microphones;
• and
• based on the calculated direction of the source, directing one or more directional sensors and/or indicators to target or avoid the source of the noise.