Question

Write a matlab code to do following steps;

i) Record your voice by sampling frequency 22 kHz

ii) Down sample the voice by 2 listen to your voice

iii) Down sample the voice by 3 listen to your voice

Please explain the code clearly. Thank you.

Answer 1

The steps include:

1. Creating an audiorecorder object.
2. Recording the voice.

(arec = audiorecorder(Fs, nbits, channels, id), for recording audio , where channels are 1 for mono and 2 for stereo)

1. Extracting the data from the audiorecorder object.
2. Reproducing audio data.

Matlab code:

clc;

clear all;

close all;

% set the parameters

fs=22050; % sampling frequency

nbits=16; % no of bits used to represent each sample

device_id= getfield(getfield(audiodevinfo, 'input'), 'ID');

audiorec = audiorecorder(Fs, nbits, 1, dev_id); % Creating the audiorecorder object

record(audiorec); % Now, speak into microphone

stop(audiorec);

data = getaudiodata(audiorec);% extracting recorded data

sound(data, Fs); % reproducing audio data

%downsampling voice by 2

fs1=fs/2;

audiorec = audiorecorder(Fs1, nbits, 1, dev_id); % Creating the audiorecorder object

speechplayer = play(audiorec); % Now, listen to the recording

stop(speechplayer);

data = getaudiodata(audiorec);

sound(data, Fs1); % reproducing audio data

%downsampling voice by 3

fs2=fs/3;

audiorec = audiorecorder(Fs2, nbits, 1, dev_id); % Creating the audiorecorder object

speechplayer = play(audiorec); % Now, listen to the recording

stop(speechplayer);

data = getaudiodata(audiorec);

sound(data, Fs2); % reproducing audio data