I also wonder if anyone here does operate in the gift, if so then what does it feel like to you when you speak in tongues and what have you seen it do to those who hear?
"Tongues", "interpretation", and "prophesy", along with any other gift employing spoken utterances all operate in identical fashion.
You "HEAR" in your spirit what the Spirit wants to communicate whether in a language you understand (as in Interpretation or prophesy) of one that you don't (as in "Tongues"). The "Interpreter / Prophet then speaks the message they've been given to the selected audience at a time dictated by the Holy Spirit.
The "Tongue" may or may not translate into the resultant Interpretation (sometimes it appears to be a "Trumpet sound" to get the congregation's attention for the Interpretation).
The "tongue" is occasionally a KNOWN LANGUAGE by somebody present hearing it. it's on record that the COMMON language is spoken and it is HEARD in one or more different languages.
The "tongue is often used in prayer, or praise with no accompanying interpretation as the Spirit speaks to God for whatever reason. some of it is laid out in 1 Cor 14.
This or that "religious paradigm / denomination" will "Make up" rules under which they think "Tongues" (or other giftings are permitted to operate, but it's nothing but "Theology" so no bug deal.
Spiritual gifts are NOT OWNED by those manifesting them, but are temporary empowerments to accomplish specific ministries at the Holy Spirit's pleasure and with HIS timing.
Personally I've spoken in "Tongues since 1973, Still do, but NEVER delivered a "Message in tongues" to a listening audience. I HAVE Interpreted, and spoken Prophetically.