According to Merriam Webster Dictionary, Audio as a Noun is defined as: "an audio signal" which refers to sounds, voices, music, songs etc. Therefore, it is more appropriate to use a Farsi word which contains all these meanings. The previous suggested translations, used "صداها" which means "the voices" and "آهنگ" which means "song'. so it is better to suggest" فایل صوتی" which is referred to any sort of voices, songs, musics, sounds etc.