Lord Corporation NVX Active Systems - Products from a manufacturer of active noise and vibration control systems for passenger aircraft. Virginia Tech Vibration and Acoustics Lab - Research at Virginia Tech. Unger Technologies, Inc - Supplier of noise and sound control products for industry. Provides details of products and applications. Frequently Asked Questions about Active Noise Control - Provides answers to common questions about active noise control including a discussion of popular misconceptions about what active noise control can and cannot do. IAC - Suppliers of noise and acoustic barriers, panels, doors, structures and test facilities. Envirotech Systems Pvt. Ltd. - Manufacturer of sound testing chambers and acoustic enclosures.