1.   And for the most part, screening out unwanted sounds has involved either bulky and hard-to-use directional microphones or inconvenient headsets.

2.   Some cameras are equipped with directional microphones that can pick up even whispered conversations.

3.   The directional microphone, although placed at your ear, picks up sounds from your mouth.

4.   Some said that the secret police were driving vans around the sprawling site equipped with directional microphones on the roof in a bid to record conversations.