Please examine the texts provided thoroughly to identify and correct any spelling, typographical, grammatical, OCR (optical character recognition), and mathematical errors, including any errors related to the square root symbol. Ensure that the entire text is properly formatted and presented in a clear, coherent manner. Only correct errors, Do not answer it.
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Texts:
a) Design a digital Butterworth IIR filter to remove random noise corrupted with a speech signal that is sampled at 10 kHz. Consider the following specifications:
Filter designing method: BLT
Speech frequency range: 0-3 kHz
Stopband range: 4-5 kHz
Passband ripple: 3 dB
Stopband attenuation: 25 dB
Show a detailed manual working. Determine the filter's order and transfer function as a function of 𝑧^(-1). (Hint: use MATLAB to simplify H(z))
(b) Using MATLAB, design the filter mentioned in part (a), plot the frequency response (in Hz), and find the transfer function of the filter as a function of 𝑧^(-1) (Note: use the bilinear command).
(c) Use the butter MATLAB function to redesign the filter. Plot the frequency response (in Hz) and find the transfer function of the filter as a function of 𝑧^(-1).
##Hint## The doctor said it may be a 4th order filter.