MP3 into text transcription

Dragon Dictation (available in the Mac App Store) can do that, but I don't know whether it understands Italian. The problem you'll encounter is that DD expects sound to reach it through the MBP's microphone (or some other microphone that's plugged into the MBP), and I don't think the MBP can "listen" to a recording that's being played from its own hard drive. You may have to play the mp3s from an iPod or other device through external speakers and have the MBP's mic "listen" to that for DD to work. You might also have trouble with the quality of your recordings not being good enough for accurate transcriptions.

I've only used DD myself on short voice messages that I dictate myself directly into my iPod or iPad (I have the iOS version of it, not the Mac OS version).

I suspect DD may have to learn a person's voice and the audio quality from a lecture room recording will be poor and inconsistent (unless the instructor uses a microphone with feed to your recorder).

You can try

MacSpeech Scribe

<http://www.nuance.com/for-individuals/by-product/dragon-for-mac/macspeech-scribe /index.htm>

It works with recordings—though, curiously, not MP3 files (perhaps a licence issue). I don't know if it does Italian, you'd have to check that yourself.

To use it, you'd have to transcribe MP3 files to something else (eg, MP4), which is not a problem, because it can be done with iTunes. However, the sound quality is a major issue. You can convert MP3 to AIFF or WAV, use, say, Audacity to filter background noise (after buying MacSpeech, you won't have money left for SoundSoap!), then use The Levelator to compress dynamics, and finally encode to MP4 (if necessary). Now, whether the game is worth the candle…