I have 2 audio files, Speech.wav and noise.wav. I want to merge the 2 audio files into one such that the noise.wav acts as a background noise for the speech audio. But the sample rates of both the files are different. the noise file has a sample rate of 8000 and the speech file has a sample rate of 48000. If I reduce the sample rate of speech file, its losing its quality. I want to add the noise to speech file without changing the speech file’s sample rate. How do I do it?