FIRST DRAFT-SWITCHING CONTROLLER FOR PERSONAL ANR SYSTEMS

摘要

This invention relates to a unique control approach that provides a means for manual or automated switching of narrowband controllers in personal active noise reduction (ANR) systems. A second related innovation links the human auditory system's physiological features to the design of a specific switching controller that implements ANR technology in audiometric testing. The design incorporates a speaker (7) as an actuator that modifies the microphone (9) sensor to reject the ambient noise. A summing junction (11) is included prior to speaker amplifier to add the controller (10) output to the prefiltered (5) audiometry (4) test signal. For a given control objective of narrowband acoustic disturbance rejection, an analog or digital feedback controller can be designed to accomplish this goal over the precise bandwidth of the disturbance(s). The new switching controller which is the key element of this invention requires that multiple feedback controllers be integrated with the personal ANR system, each one designed for maximum suppression/minimum spillover over specific and different narrowbands of frequencies.