The pressure difference between the two sides produces its directional characteristics.

Gun-mikes are generally restricted to outdoor use; indoors, sound reflections off walls defeat the directional characteristics to a large extent.

LEDs do not emit light in all directions, and their directional characteristics affect the design of lamps.

If it's considered formal communications as they occur in traditional military organizations, messages have a "one-way" directional characteristic.

The directional characteristics of the site antenna array.

Horns have been used to modify the directional characteristics of the produced sound waves.

In order to attain the proper directional and spectral characteristics, a pyranometer's main components are:

For the high frequencies, some other method must be employed to attain directional characteristics that match those of the lows and mids.

The size of the mid-range driver is 4 inches in diameter as to match the directional characteristics of the entire speaker.

One should not use double diaphragm microphones because of the produced unbalanced directional characteristics and the larger phase responses.