Contaminants, especially, polypropylene fibers are a cause for worry during the high speed processing of cotton in the textile and related industries. CNDE in collaboration with Sieger Spintech Pvt Ltd, Coimbatore has developed a sonic system that uses proprietary Ultrasonic imaging to identify the contaminants based on density. The high accuracy and speed of the sensors enable identification of white polymers and hidden contaminants of different densities Signals from sensors are efficiently processed by unique embedded sonic signal processors. The system operates on cotton that is processed at speeds in excess of 10 m/s and has the ability to detect and remove a single fiber contaminant embedded inside the cotton. The sonic system as well as the sono-optic systems (where an optical system is used in addition to the sonic detection) have been installed in several industries in India, South-East Asia, and Europe by Sieger Spintech.