When the apostles were speaking in tongues, not only were they speaking in other languages, they were speaking in the exact dialect of those around them. This was even more miraculous as they were Galileans, known for being uneducated and having an accent.

It was apparent that they were clear, of a sound mind, and in control of themselves. They were not simply babbling without meaning.

When we pray (talk to God), or minister/preach to others, we are to avoid vain repetitions, or babblings without meaning.

This indicates that there is no Heavenly language as when Pentecost occurred it was done with known languages and understood by those around.

One of the reasons we don’t see the power of the Spirit in our lives is because we don’t ask for it.