The Zimple-Gate is a noise remover software audio plug-in. The plugin is an Audio Units format, hence it can be used only in Mac OS X and it has been developed to be mainly used with Apple's Garageband software. While it may be used with other software as well, we do not fully support those. 

A noise gate is generally used to remove unwanted noise or sounds from a recorded audio track. To operate the gate, you have to first set the Threshold level; any sounds on the track that have a an amplitude level below this threshold will be muted. Think about this as an actual gate that will close in front of any sound that is below this threshold and open for sounds louder than the threshold.

In addition, you will have to set the Release and Attack time. The Release determines how fast the gate will close once it detects sounds below the threshold, while the Attack determines how fast the gate will open once it detects louder sounds. The more you will use the Gate, you will understand the importance of tweaking these parameters yourself, based on the audio content, as opposed to using a setting provided by us. Depending on the nature of the sound (more transient or with a smoother envelope), different Attack and and Release settings will be necessary to obtain a natural result; even an infinitesimal difference in the settings can make a noticeable difference on the sound. We enourage you to experiment with these levels, however, we also made-ready a few presets for you, that you can select under the Preset Menu.

 Download
Zimple-Gate 

A few things you should know about using a noise gate:

• The Gate does not know the difference between "wanted" and "unwanted" sounds if they have the same amplitude level. Therefore, you will have to be careful using the gate and set the threshold low enough so that you eliminate noise, but do not loose material that you actually want.
• Unless you are very confident of what you are doing, we encourage you to use the gate during the mixing process and not during recording. It is better to have an intact track that you can process with the gate during a mix, than record a track with holes in it!
• Sounds with a transient attack (e.g. snare drum) are likely to require a shorter release setting than sounds that have a smoother attack (e.g. voice).
• The attack setting also should be set depending on the nature of the sound and the reverberation specific to the recorded soundfield.  
• On the Zimple-Gate, the status LED blinks when the gate is closed. 
• The Zimple-Gate runs on Apple's Garageband, Logic and any other audio program that supports Audio Unit plug-ins with Cocoa GUI (for a list of these programs visit the support page.