1. MONO SOUND

2. In everyday life we listen with two ears. As we compare these two separate sound images of the external world, they build a three dimensional impression from which the direction and distance of sound is estimated. Non-stereo television sound is not as sophisticated as this. It presents a monoaural (mono)representation of sound in space. The only clue to distance is loudness; direction cannot be conveyed at all. Listening to mono reproduction, we are not able to distinguish between direct and reflected sounds, as we can when listening to stereo. Instead, they become intermixed, so that the sound is often “muddy” and less distinct. In mono sound, we become much more aware of the effects of reverberation. Because the audience cannot easily distinguish direction and distance, the microphone needs to be carefully positioned. You need to be careful that:  Too many sound reflections are not picked up.  Louder sounds do not mask quieter sounds(particularly in a musical production where instruments are used)  Extraneous sounds do not interfere with the ones we want to hear.

3. STEREO SOUND Stereo creates an illusion of space and dimension. It enhances clarity. Stereo gives the viewer the ability to localize the direction of sound. This localization give the audience a sense of depth-a spatial awareness of the visual image and the sound. However, because the speakers in television receivers are quite close together, the effect can be somewhat limited. Sound quality and realism are enhanced, but our impressions of direction and depth are less obvious. To simplify sound pick-up, mix central mono speech, with stereo effects and music. In a television production always maintain direction(such as mic left to camera left), and hold the mic still. In a stereo system, reverberation even appears more pronounced and extraneous noises such as wind, ventilation, and footsteps are more prominent, because they have direction, rather than merging with the overall background.

4. SURROUND SOUND Surround sound can provide a sense of envelopment when mixed correctly. Instead of the one channel for mono or the two channels for stereo, 5.1 surround has six discrete(distinct, individual) channels: left front and right front(sometimes called stereo left and right), center, a subwoofer for low frequency effects (LEFs), and left rear and right rear speakers(sometimes called surround left and right). The feeling of depth, direction, and realism is obtained by the audio personnel panning between the five main channels and routing effects to the LFE channel.