1. A method of processing a multichannel signal, said method comprising: for each of a plurality of different frequency components of the multichannel signal, calculating a difference between a phase of the frequency component in a first channel of the multichannel signal and a phase of the frequency component in a second channel of the multichannel signal; based on information from the plurality of calculated phase differences, calculating (A) a value of a first coherency measure that indicates a degree of coherence among directions of arrival of at least the plurality of different frequency components in a first spatial sector and (B) a value of a second coherency measure that indicates a degree of coherence among the directions of arrival of at least the plurality of different frequency components in a second spatial sector that is different than the first spatial sector; calculating a contrast of the first coherency measure by evaluating a relation between the calculated value of the first coherency measure and an average value of the first coherency measure over time; calculating a contrast of the second coherency measure by evaluating a relation between the calculated value of the second coherency measure and an average value of the second coherency measure over time; and indicating one among the first and second spatial sectors, based on which among the first and second coherency measures has the greatest contrast, wherein each of said first and second channels of the multichannel signal is based on a signal produced by a corresponding one of a pair of microphones, and wherein at least one among said calculating the difference, said calculating the value of the first coherency measure, said calculating the value of the second coherency measure, said calculating the contrast of the first coherency measure, and said calculating the contrast of the second coherency measure is performed by at least one processor.