Equiripple bandpass FIR filter design for speech signals: Order optimization for frequency range of 300 Hz to 4000 Hz

Speech signal varies from a frequency range of 300Hz to 4000Hz and can be filtered using various types of filters. This paper demonstrates the design of Equiripple Bandpass FIR filter specific to the application of speech signal by optimizing the order, first stopband frequency and second stopband frequency of the filter simultaneously using MATLAB Filter Design & Analysis Tool and mathematical computations for a range of values. A 3-dimensional data analysis approach has been considered to design the required stable filter.