The video contains a huge amount of information. But without sound even the best quality picture is not able to arouse the emotions of the viewers. Most likely people will remain indifferent and turn their attention to something else.
Moreover, numerous tests and studies showed that the sound quality is directly related to the viewing experience. The movie with the bad sound in comparison to the one where the sound was good (clear and pure) respondents evaluated as worse. This is due to the peculiarities of psychology: human impressions are formed by the signals coming from the different channels of perception.
If you create a video, you need to pay special attention to the quality of audio tracks. One of the most important aspects of quality film sound is the volume balance. There are two methods for adjusting the volume balance in the video: automatic and manual. Below are brief descriptions of both methods.
Adjusting volume balance by compressor
The easiest way to maintain the signal at a relatively stable level is to use a limiter or compressor. The aforementioned devices (or software equivalents) reduce the dynamics of sound. As a result, the quiet areas are becoming more discerning and loud. In the same time the zones where the signal has a high volume become quieter.
A great advantage of this method is a high speed of processing. You can for a few minutes to compress as individual tracks (speech or music) or the entire audio mix.
However, the compression should be used very carefully, because the strong compression smoothed dynamics, and nuances become less noticeable. As a result the artistic value of the audio track is sharply reduced.
It is important that final result of compression must be evaluated not only visually (based on the indicators), but also by ear. Sound volume displayed by indicator and subjectively perceived volume is not always the same.
Here are several parameters that have a psychological impact on the human perception of loudness:
- presence of short pulses
- frequency spectrum of the sound track
- masking some sounds by other ones
That is why track that was subjected to compression should be listened by using high-quality speaker system. Additional listening through headphones gives the opportunity to hear slight defects in the high frequency part of the spectrum.
Manual adjustment of volume balance
Although this option is more time consuming, it allows achieving the best results. Virtually all modern video and audio editors, have volume control via the envelopes. Manual adjustment of volume balance is carried out, step by step. After listening to a small segment of the audio track, you can define whether it needs to adjust the volume or not. In addition graphical images of sound show problem areas on which to add or reduce its volume.
Always keep a backup copy of the original audio files. If the work was done improperly, you may return to the starting point and correct the mistakes.