HW1.1 Hetong Li ECE301Fall2008mboutin - Rhea

Wav Files

• a. part a (normal speed)
• b. part b (fast speed)
• c. part c (higher pitch)

Matlab Code

%Hetong Li
%09/01/08
%ECE301 hw1.1

clear;
clc;

% PART A

delta = 0.0005;
H=0:delta: 1;          %half
Q=0:delta:0.5;         %quacter
DQ_time=0:delta:0.75;  %dotted quacter
EN=0:delta:0.25;       %one eighth

%Assign signals for each used note
AH = sin(2*pi*220*H);
BQ= sin(2*pi*493.88/2*Q);
DBQ=sin(2*pi*277.18*Q);
DDQ = sin(2*pi*293.66*DQ_time);
DQ = sin(2*pi*293.66*Q);
EEN =sin(2*pi*329.63*EN);
GBQ=sin(2*pi*369.99*Q);
GQ=sin(2*pi*392*Q);
GEN=sin(2*pi*392*EN);
FEN= sin(2*pi*349.23*EN);
GBEN=sin(2*pi*369.99*EN);

notes= [AH BQ DBQ DDQ EEN GBQ GBQ GQ GEN GEN DQ EEN FEN GBEN];

sound (notes,1/delta);
wavwrite(notes,1/delta,32,'music-a.wav');

% PART B

%half the duration
%we will hear the some plays at twice speed as before

delta = 0.0005;
H=0:delta: 0.5;
Q=0:delta:0.25;
DQ_time=0:delta:0.375;
EN=0:delta:0.125;

AH = sin(2*pi*220*H);
BQ= sin(2*pi*493.88/2*Q);
DBQ=sin(2*pi*277.18*Q);
DDQ = sin(2*pi*293.66*DQ_time);
DQ = sin(2*pi*293.66*Q);
EEN =sin(2*pi*329.63*EN);
GBQ=sin(2*pi*369.99*Q);
GQ=sin(2*pi*392*Q);
GEN=sin(2*pi*392*EN);
FEN= sin(2*pi*349.23*EN);
GBEN=sin(2*pi*369.99*EN);

notes= [AH BQ DBQ DDQ EEN GBQ GBQ GQ GEN GEN DQ EEN FEN GBEN];

sound (notes,1/delta);
wavwrite(notes,1/delta,32,'music-b.wav');

% PART C

%Change the duration back to part a
delta = 0.0005;
H=0:delta: 1;
Q=0:delta:0.5;
DQ_time=0:delta:0.75;
EN=0:delta:0.25;

%as we replace t with 2t,so double the time in signal function
%which also means double the frequency of each signal
%we will hear a song with higher pitch

AH = sin(2*pi*2*220*H);
BQ= sin(2*pi*2*493.88/2*Q);
DBQ=sin(2*pi*2*277.18*Q);
DDQ = sin(2*pi*2*293.66*DQ_time);
DQ = sin(2*pi*2*293.66*Q);
EEN =sin(2*pi*2*329.63*EN);
GBQ=sin(2*pi*2*369.99*Q);
GQ=sin(2*pi*2*392*Q);
GEN=sin(2*pi*2*392*EN);
FEN= sin(2*pi*2*349.23*EN);
GBEN=sin(2*pi*2*369.99*EN);

notes= [AH BQ DBQ DDQ EEN GBQ GBQ GQ GEN GEN DQ EEN FEN GBEN];


sound (notes,1/delta);
wavwrite(notes,1/delta,32,'music-c.wav');