Steps
Create the sample.wav file.

$ arecord -r 16000 -f S16_LE -c 1 -t wav sample.wav

Compile the amplify-signal.c file.

$ gcc amplify-signal.c

Execute the build file

$ ./a.out

Plot the files

$ python3 plot.py sample-modified.wav

Note: If the python packages matplotlib, numpy, wave are not installed
then install the packages.