# Calculate the SNR of wav file?

I am doing a project in which i have a "recorded voice". Now i have applied the noise reduction and get the "filtered voice". Now i want to calculate the SNR of recorded voice and filtered voice in matlab. I do not have pure voice for reference (As in all the previous post, pure signal is taken as reference in calculating SNR). I am confused how to do it. Please help !!

When you dont have the exact voice as a reference you can only go to estimate/measure the noise. Assuming you are facing white noise, the simplest thing is to look for either time-domain or frequency-domain parts of the signal, where no voice is present. In these parts there is only noise. Hence, if you measure the average signal power in these parts, you get the noise power P(noise). Then, you measure the overall signal power, which is P(voice) + P(noise). Finally, you can have $$SNR=\frac{P(voice)+P(noise)-P(noise)}{P(noise)}$$