NEIM1031 Noise Eliminating In-Line Module The NEIM1031 Noise Eliminating In-line Module incorporates the latest Digital Signal Processing (DSP) technology to remove unwanted background noise and interference from speech, enabling you to concentrate and listen .....”Stress Free” Features: Fully Adaptive noise cancelling Noise cancellation 9 - 35dB User selectable noise cancelling levels Audio input socket Line level input and output External speaker socket Headphone socket Greatly improved signal to noise ratio Easy to install with adjustable mounting bracket Noise Cancellation on / off switch 12 – 24Vdc operation Input overload warning LED Optional extras available