First Audio Learn Mode cannot be used on the second and subsequent BNR modules assigned to the same mixer channel. First Audio Learn mode is triggered by the start of playback and uses the first 16 milliseconds of audio to create the Noise Signature. Due to the processing delay inherent within BNR, second and subsequent modules using First Audio Learn mode would actually Learn silence if Learn is armed prior to playback. Alternative Learn methods for this scenario are as follows:Method 1: Begin Playback before activating First Audio Learn.First Audio Learn mode can be performed during playback. Once playback has begun, the second and subsequent BNR modules can be opened and Learn performed. Playback must begin sufficiently early for the desired noise section to be used for Learn. Alternatively, Pro Tools can be put in Loop Mode, and the isolated noise section (which must be larger than 0.5 seconds) can be selected and looped during Playback. The second and subsequent BNR modules can then be opened and Learn performed.Method 2: Use Last Audio Learn ModeUsing Last Audio Learn Mode in the later BNR modules provides another alternative. Refer to the Digidesign Plug-Ins Guide for details on using Last Audio Learn Mode.