This is a device that you can program to recognize certain noises such as your weapon's fire and it will automatically filter out the noise. Now this can become extremely useful when say you are in a gunfight and need to hear if some one is sneaking up on you. All you have to do is program the sound to cut out certain background noises and even amplify others. This is normally considered a black market device or military grade (such as special forces or the UPF Intelligence Agency). It runs a cost of 5,000 credits and is very light (less than a kilogram altogether).
Inspiration from Shadowrun Role-Playing Game