After recording numerous takes all across your session, you will be left with a lot of regions. It is likely that only a small amount of the regions recorded will contain information which you actually require, the rest will be made up of silence and the noise just before a performance.
You may think that the playback of silent region information within a session has no effect, however the reality is that Pro Tools still uses vital processing power here. This is the reason why one of the most common first steps during editing is to remove any useless region information. The problem with this process is that it can take a fair amount of time to trim each of the individual regions, this is until now with the introduction of ‘Strip Silence’ within Pro Tools.
Strip silence is an in-built feature of Pro Tools which will detect audible information within regions (based on a threshold set by the user), and then strips them away from the silence, leaving you only with the information you require. The plug-in it is not limited to working with a single region, technically you could highlight every region within your session and apply the process, although this of course depends on the level variations between regions which could be missed by a set threshold.
The editing tool offers four adjustable parameters which will determine what is detected as necessary information as well as how much region boundary trimming occurs.
Strip Threshold: This will determine how loud a signal needs to be so that it is perceived as ‘required sound’ as opposed to silence or unwanted noise. After selecting a region, the threshold should be increased until a box appears around what you would like to keep, it is not a problem if a few areas are not detected as then can be removed manually afterwards.
Min Strip Duration: This sets the shortest amount of silence which should be removed. This is useful in making sure that short pauses between recordings which could include some required sound decay are not removed.
Region Start/End Pad: These two parameters decide how much padding is left at the beginning and end of a trimmed region, much like the minimum strip duration, these are useful settings to ensure that any required information which is perhaps below the set threshold is not removed.
Quick Tip: Strip Silence is a non-destructive editing tool which means that no matter how much region information is trimmed, it can always be recovered afterwards.
So lets have a look at this effect in action, in the below example I used a short vocal region consisting of both silence and sound.
We will start by increasing the threshold until the plug-in draws a box around the audio information as shown below. Most of the time the silence and audio should be easily to tell apart, however when you can’t seem to find the right threshold setting it is best to set it lower and pick up a little silence as opposed to setting it too high and removing something you may need.
If short amounts of silence between phrases are getting cut off when you would like to keep them, then simply increase the minimum strip duration until only the longer unwanted areas are highlighted.
It is generally best to leave a little pad at the beginning and end of each region, even if you have to apply a fade afterwards. It is generally not of a benefit to have a complete cutoff where the vocal starts as this can be very audible which of course we do not want.
After your happy then click ‘strip’ and you should be left with the only bits you really need producing a less demanding playback.
Selecting ‘extract’ will remove the solid audio material leaving only the silence and noise. The ‘separate’ option will split the regions at the defined points created by the tool.
You will notice there is also a ‘rename’ option, this will allow you to rename the remaining regions, after clicking you will be presented with a dialog box which will let you choose its new name as well as the number sequence the following regions will follow.