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

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

controller’s 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);

x =wavread(\'s1.wav\');

% 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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