1. Lab No.05
Signal Operations applied
to an audio signal
Designed by : Dawar Awan
dawar@cecos.edu.pk
CECOS College of Engineering and IT
March – July 2012

2. Audio in MATLAB
 Reading a Saved wav file
>> variablename=waveread(‘filename’)
 Reading a 2sec chunk of mic’s sound into MATLAB
 Playing back a wav file
CECOS College of Engineering and IT
March – July 2012

3. Signal Operations
 Delay of 10000 samples
CECOS College of Engineering and IT
March – July 2012

4. Signal operations
 Time reversed signal
CECOS College of Engineering and IT
March – July 2012

5. Signal operations
 Amplitude scaling
CECOS College of Engineering and IT
March – July 2012

6. Signal operations
 Adding an extra tone to the audio signal
CECOS College of Engineering and IT
March – July 2012

7. Signal operations
 Down sampling the audio signal by a factor of 3
CECOS College of Engineering and IT
March – July 2012

8. Signal Operations
 Changing the samples per second send to sound card
CECOS College of Engineering and IT
March – July 2012

9. Task
1. Write a MATLAB code that adds echo to an audio signal.
hint: An echo effect can be created by adding the original signal to its
delayed version.
CECOS College of Engineering and IT
March – July 2012