Audio Video Recording And Editing 4(1+3)

Lesson 11: Editing

Editing Digital Audio

Synchronizing sound sources
There are two means of maintaining synchronization between one or more soundtracks originating at the same or different times. The technique used with either system is basically the same: one uses digital or analog audiotape and the other uses the ability of a sound application within a computer to record and process sound inputs individually or in groups. Multi-track audio tape recorders allow the sounds recorded on one track to be played at the precise speed at which the original recording was made while additional sounds are added on a parallel track.

Sound mixing techniques
Mixing is a process by which various soundtracks are blended together or combined with each other. Individual soundtracks for speech, sound effects, and music, for example, are first edited into sequential order, often in conjunction with visual images, before they are mixed together to form one soundtrack.

Automatic gain controls (AGCs) are sometimes used to maintain consistent audio levels during audio recording and dubbing. This method too often boosts background noise to unpleasant levels during nonspeaking passages.
A mix is carefully preplanned on a mix log or audio cue sheet. A mix log or audio cue sheet indicates all the volume and EQ changes and transitions for every sound source the sound mixer must control. It is organized sequentially according to the overall time of the program.

Synchronous dialogue is generally recorded simultaneously with accompanying visual images. The sounds and images are then edited at the same time in the same format.

Sound effects
There are basically three kinds of sound effects: prerecorded library effects, spot recorded effects, and actually recorded effects. Library effects are cataloged and maintained on photograph record, audiotapes or CDs for storage convenience and accessibility (figure10.13). Spot effects are created in a sound studio to duplicate the supposed off-screen or on-screen source. Actually effects are recorded outside the sound studio. They either accurately reproduce a particular sound or create a vivid sound impression. Synchronous sound effects are immediately dubbed to the videotape or film format of the visuals so that they can be edited in synchronization with corresponding visual images.

Editing music
Music for a film or television program can come from a variety of sources. Library music, which has been prerecorded on a CD, audiotape, or phonograph record, is often used to accompany visual images and other sounds. There are two basic approaches to the problem of mixing music and speech sounds. One approach is to lower the level of the music “down and under” immediately before the delivery of a line of dialogue or narration, and then return the music to a normal level after the speech has concluded. A second approach is to keep the music at a consistently low level. If music is mixed at its full value, the speech sounds that accompany it will be difficult to understand. Even when the music is kept at a consistently low level, if is important to have clear and distinct dialogue and narration. An underlying assumption of both these approaches to mixing music and speech is that the speech must be clearly understood. But it is sometimes necessary to hear the music at its full value, particularly when its place, intensity, and mood are essential to the establishment of a particular feeling.

Dubbing
Dubbing is an important part of post-production, particularly in fiction. When shooting on location, the actors' dialogues get mixed with undesir­able ambience sounds and are not fit for broadcast. Dubbing is the process of re-recording the lines to correct mistakes on the sound track. The actor, usually the one who played the role, or a professional dubbing artiste is called to what is known as a dubbing studio. The dubbing studio is equipped with audio-video playback (player and monitor) and recording equipment. The on-location dialogue is played back for the dubbing artiste. The dubbing artiste listens to the dialogue through headphone a couple of times and repeats it for recording in a manner appropriate to the scene. It is the responsibility of the dubbing artiste, the audio engineer, and the direc­tor to ensure that the dub synchronises with the original dialogue track.