> 174 Czech adults listened to 5 minutes of Māori... They were then tested on new audio clips from either Māori or Malay ... and asked to say if they were hearing the same language as before or not. The test phrases were acoustically filtered to mimic speech heard in the womb. This preserved melody and rhythm, but removed the frequencies higher than 900 Hz which contain consonant and vowel detail.

> Listeners correctly distinguished the languages more often than not

Just to be clear what was actually tested. The conclusions seem pretty heroic to me given the extremely limited nature of 'language learning' that happened here.