Bio-inspired frequency-adaptive acoustic system
Standard microphones are generally designed with a static and flat frequency response in order to address multiple acoustic applications. However, they may not be flexible or adaptable enough to deal with some requirements. For instance, when operated in noisy environments such devices may be vulnerable to wideband background noise which will require further signal processing techniques to remove it, generally relying on digital processor units. In this work, we consider if microphones could be designed to be sensitive only at selected frequencies of interest, whilst also providing flexibility in order to adapt to different signals of interest and to deal with environmental demands. This research then introduces the fundamentals of a novel concept of signal processing at the sensor level. An acoustic signal processing framework integrating a functional prototype system was engineered to support the concept of a frequency agile sensor. That is a concept where the “transducer becomes part of the signal processing chain” by exploring feedback processes between mechanical and electrical mechanisms that together can enhance peripheral sound processing. This capability is present within a biological acoustic system, namely in the ears of certain moths. That was used as the model of inspiration for a smart acoustic sensor system which provides dynamic adaptation of its frequency response with amplitude and time dependency according to the input signal of interest.