Can I add white noise to signal without using awgn?

Hi, novice here,I m trying to add gaussian white noise to a .wav file , but my assignment only mentions σ=0.01 and the randn function as tips, nothing about the awgn function. How can I accomplish that ?

[Mathieu NOE]

hello

if you use randn, remember that this signal will have sigma = 1 standard deviation

so if you need sigma = 0.01 noise signal it's simple :

noise_signal =  0.01*randn(1,samples) ; 

[dimakopoulos alexandros]

Thank you very much!

[Mathieu NOE]

you're welcome