ABSTRACT
Objective The fractional realization of delayed parameters will occurs when using microphone array technology in cochlear implants. To study the design and mismatch feature of fractional delay filter so as to meet the requirement of fractional delay realization in cochlear implants. Methods According to the characteristics of small cochlear implants and delay requirements, a fractional delay filter was designed by least mean square method. Results The fractional delay filtering method based on least mean square interpolation can achieve fractional delay, and can minimize the average error and the mean square error of the whole frequency band. Conclusions The fractional delay filter based on least mean square interpolation has the features of mismatch and high-order flat error, which makes it have theoretical and engineering value and providing a parameter selection method for the design of fractional delay filter.