Load and Play Wave File (`.wav`) on MATLAB
When you load Audio file to MATLAB you basically load array of numbers.
When you play Audio there is a parameter which is needed - Sampling Rate.
This is what tells the player how fast to play the data.  

Think if you load a file with 1000 samples. How long should is the audio?
Unless you supply some information, the player can not know (MATLAB just use a default which doesn't match your data).

If you look at the documentation of the sound() function you'd see there is an option to use it as sound(audioSignal, samplingRate).

In order to get the Sampling Rate of a Wave file use: [audioSignal, samplingRate] = audioread(filePath). Read more at audioread().