While YouTube itself does not natively stream or store audio at a true 320 kbps bit rate, many tools allow you to convert and save video audio directly into this high-quality format for offline listening.
At 320kbps, an MP3 file is virtually indistinguishable from a CD-quality WAV file to the human ear, especially when played through standard headphones or car speakers. The YouTube Audio Reality Check 320 kbps mp3 youtube download