First, "nihongo" means Japanese in Japanese. "Sou Matome" might be a specific course or series. I recall that there are several Japanese learning resources with similar names, like "Sou Matome Nihongo Kyoushitsu" or something like that. Maybe "Sou Matome" is a well-known series? I should check if that's the case.
I should first verify the existence of such a series. Let me think. "Sou Matome" is sometimes translated as "All in One," and there are books like "Sou Matome Nihongo Kyoushitsu" by Japanese educators. The publisher might be a company like Asan Publishing or similar. If the series includes audio, they might have CDs or offer downloads. nihongo sou matome n4 audio download portable
Another angle is that some books come with online access codes for audio. The user might have purchased a physical copy and now wants to extract the audio for easier portability. In that case, instructions on using software to convert CD audio to MP3 or transferring digital files to a portable player could be useful. First, "nihongo" means Japanese in Japanese