Adding noise (with a specified SNR) to a sine wave

Hello people, another question here. I have succesfully created my first audio signal using a sine wave with the specs below. I tried adding some noise at an SNR of 2.01dB but I am not 100% certain that I did it correctly. For my sampling time, I assumed it would be the # of samples/sampling rate? I would greatly appreciate any feedback possible.

% Generate a sound sample which consists of
%   22050s-1  sampling rate
%   2^14 samples
%   Sine wave
%   Amplitude 0.187 
%   Signal frequency (1.6)*187 Hz
%   Add random noise with 
%   SNR = [187/90] dB
 
Fs = 22050;
Ts = 1/Fs;
%Time = Samples/Sampling rate = 0.74s
tt = 0: Ts : 0.74;
ff = 187*1.6
ss = 0.187 * sin(2*pi*ff*tt)
SNRdB = 187/90;
SNR = 10^(SNRdB/10);
 
noisy_signal = ss + SNR .* rand(size(ss));
 
sound(noisy_signal,Fs)

[Walter Roberson]

awgn() instead ?

[xRah]

How would I do that? I tried using that function, but I fail to recognize any difference.

[xRah]

And I am not sure how to use it correctly within my code.

[Walter Roberson]

noisy_signal = awgn(ss, SNRdb, 'db');

[Abhinav]

noisy_signal = awgn(ss, SNRdb, 'measured'); % Changed 'db' to 'measured'. This one worked for me.