They just felt a high and think it's holy spirit or something.
Just FYI, according to many Christian scholars, when their bible says one of the gifts of the "holy spirit" speaking in tongues, it means actual foreign human languages like Latin or Swedish or Japanese, not gibberish. Most of them agree on that and think that talking gibberish like the Pentecostals do has nothing to do with what was meant in the text.
And analysis has be done on that gibberish and it has shown that is based on the language that the person speaks. An English speaking person's "speaking in tongues" gibberish has more similarities to English whereas a Spanish speaking person's gibberish is like Spanish. This debunks the claim that it's inspired from some higher source.