For a large number of applications the person speaking is sitting or standing in front of the microphone, and only his voice has to be heard. Hence for these applications especially conferences and meetings, the event organizer will use a directional microphone for best quality audio. Usually the microphones used in mobile phones and microphones for some applications are designed to pick up sound from all directions, increasing the noise and adversely affecting the audio quality. So to reduce the background noise, directional microphones are being used in conferences, where the speaker has to be heard.
Pickup pattern
A directional microphone is usually defined in terms of the pickup pattern, the area around the phone from which the sound waves are picked up and magnified by the microphone. Omni-directional microphones are picking up sound in all directions around the microphone resulting in noise due to which the audio is not clear. In contrast, most of the directional microphones are designed to pick up sound only from the front of the microphone, a small amount of sound from the sides. No sound from behind the directional microphone is picked up greatly reducing the noise and other disturbances.
Types of directional microphones
The most popular type of directional microphone has a cardioid or heart shaped pickup pattern. In this microphone, the sound waves mostly from the front side of the microphone are pickup up and converted into electrical signals. The hypercardiod directional microphone is a variant of the directional microphone, designed to isolate the speaker or musician, so that there is no disturbance from other sources. Supercardiod microphones are typically used by film makers to isolate the speaker though they will pickup a small amount of noise from the background. Goose-neck microphones have adjustable skinny necks which capture the close up audio. The unidirectional or lobar microphone is another directional microphone only capturing sound in front.
Applications
Directional microphones are widely used in meetings and conferences where the voice of each speaker has to be clearly heard by others participating in the meeting. Additionally these directional microphones are also used in a room with poor acoustics, or background noise so that the person speaking is heard clearly. Hypercardiod microphones are used when recording a musician playing a musical instrument in a studio. Video film makers often want a small amount of background noise to make the video more realistic, so they use supercardioid microphones. Goose-neck microphones are ideal for meetings where the height of the speakers differs since the height and orientation of the microphone can be easily adjusted.
Benefits
Often background noise can adversely affect the quality of audio, so that others in the conference or meeting cannot hear the speaker clearly. The main benefit of using a directional microphone is that the background noise is eliminated to a great extent, improving the quality of audio recorded. The person using the directional microphone for recording music, speech or other audio will not have to waste time, effort removing the background noise. There are different types of directional microphones, and it is advisable to check the pickup pattern before purchasing a microphone for any application.