Final Cut (and other editing apps) will accept many kinds and formats of audio for import into the Browser or Timeline.
However, just because they will, doesn’t mean you should! 🙂
If you import compressed audio, for example, in MP3 or AAC codecs, or audio in a different bit or sample rate than your Timeline (such as 44.1 KHz, 32 KHz or 12-bit), you will often hear clicks, pops, and audio dropouts while editing, which is distracting for your creative process, and in many cases your audio will require rendering before you can even hear it, which sounds like “beep-beep-beep-beep” and wastes a lot of your time.
Our solution is to batch convert all audio to 48KHz, uncompressed, stereo or mono for editing before importing.
We use DV Kitchen for this, it comes with a preset already designed for this.