# A pilot is flying a Cessna 172 (a single engine propeller aircraft)

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A pilot is flying a Cessna 172 (a single engine propeller
aircraft) while listening to the instructions from a female air
traffic controller. An audio file that the pilot hears is
uploaded on blackboard, which contains the noise
generated by his Cessna aircraft. Please use the theory
and technology you have learned in AAE 301 to process
the audio file by removing the aircraft noise. Hint: (1) The
Matlab command to load a wav sound file is audioread or
wavread, and the command to write a wav sound file is
audiowrite or wavwrite. (2) The voiced speech of a typical
adult female has a fundamental frequency from 165 to 255
Hz. (3) The aircraft noise in this audio file contains low
frequencies AND high frequencies (your AAE 301
instructor has already helped remove most noise of
frequencies that overlap with those of the air traffic
controllers voice). I was wondering how to cancel out the
frequencies above 3000 Hz and below 165 Hz using
Fourier transforms in MATLAB.
Solution
you can follow these steps, but to canel frequencies
between 165 hz and 300 , you can apply mel filter bank,
you can construct MFCC(mel frequncy cepstral coeficents).
i will paste the code.
clc;
clear all;

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close all;
Fs = 44100;
t = linspace(0,1,Fs);
% Specifying the filter
%\'Fp,Fst,Ap,Ast\' (passband frequency, stopband
frequency, passband ripple, stopband attenuation)
hlpf =
fdesign.lowpass(\'Fp,Fst,Ap,Ast\',4.0e3,4.1e3,0.5,50,40e3)
;
% Designing the filter
D = design(hlpf);
% Applying the filter
y = filter(D,x);
sound(y,Fs)
%x1=ssubmmse(im1,8000);%noice removal
%features1=melcepst(x1,Fs);
z=melcepst(y,8000);
but melcepst need other functions to execute
instead that you can do fft using function fft
melcepstrum includes following steps
fft-> log->mel filterbank->iDFT
this process gives only human audible range.then you can
cancel cancel out the frequencies above 3000 Hz and
below 165 Hz .

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A pilot is flying a Cessna 172 (a single engine propeller aircraft) while listening to the instructions from a female air traffic controller. An audio file that the pilot hears is uploaded on blackboard, which contains the noise generated by his Cessna aircraft. Please use the theory and technology you have learned in AAE 301 to process the audio file by removing the aircraft noise. Hint: (1) The Matlab command to load a wav sound file is audioread or wavread, and the command to write a wav sound file is audiowrite or wavwrite. (2) The voiced speech of a typical adult female has a fundamental frequency from 165 to 255 Hz. (3) The aircraft noise in this audio file contains low frequencies AND high frequencies (your AAE 301 instructor has already helped remove most noise of frequencies that overlap with those of the air traffic controller’s voice). I was wondering how to cancel out the f ...
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Anonymous
Awesome! Made my life easier.

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