to change the amplitude of a .wav file

I am new to Matlab and im trying to change the amplitude of a .wav file. i have exported the data and Fs. i just dont know how to now increase/decreas the aplitude of the wav.

the code below shows what i have done,

thanks for any advice given.

plot(data);
soundsc(data,fs);

Answer 1

[Image Analyst]

Try multiplying by a scaling factor:

amplificationFactor = 1.1; % Ten percent gain.
data = data * amplificationFactor;
plot(data);
sound(data, fs);

You might be interested in my File Exchange entry that allows you to plot the waveforms of all the files in a folder:

https://www.mathworks.com/matlabcentral/fileexchange/72431-plot-audio-file-waveforms?s_tid=srchtitle

[Femi Okome]

thank you very much. that now works and i can also see the gain change on the graph. one more thing, what would be the best way to calculate the plot value in dB.

[Image Analyst]

You probably need to square the signal to get power then use the formula here:

https://en.wikipedia.org/wiki/Decibel#Power_quantities