Also, any university train Missionary like Montgomery, Helen are Linquists.
Isn't that a historical figure rather than a university?
There are some people who study linguistics who claim no speaking in tongues is human language. This doesn't fit the historical record, or the Biblical one for that matter. It may have to do with their samples. One study I saw a video about rejected speaking in tongues as a genuine language because the speaker spoke in a high pitched monotone rather than with the intonation of normal language, but I have heard people pray in English the same way with the same tone.
I would allow for different categories of what proports to be 'speaking in tongues.' First, I would say some are genuine human languages, current living languages or 'dead' languages. The second category I suspect may occur are tongues of angels, whatever those are like. A third category might be psychologically manufactured tongues. Someone really wants to speak in tongues to 'join the club' in a church where there is a lot of pressure to speak in tongues and where people are taught basically to blank their minds and say what comes to them while other people gather around them and 'speak in tongues.' I was in a big room full of people who all seemed to be saying 'bababa' or 'bada bada bada' once overseas. Then the fourth category might be a demonic counterfeit. Demons can speak in various languages, so they might fake tongues.
The Bible does not teach us to be afraid that God will give us something evil when we ask for the Holy Spirit, so i do not think believers should worry about accidentally getting a demonic tongue or even a fake tongue. And since we do not know how angelic languages are inflected for meaning, there would be no way to distinguish between categories two and three when it comes to tongues, so Linguistic studies of this sort would be inconclusive.
But there are linguists who teach in seminaries or Biblical language programs. Or at least those with some expertise in some branch of linguistics or training in linguistics from the philological perspective. For example, Hebrew language scholars may have some training in Semitic Linguistics.
The Summer Institute of Linguistics/ Wycliff folks often have Linguistics training which helps them learn new languages so that they can translate the Bible into these languages. This may involve documenting the language and creating an alphabet that takes into account unique phonetic sounds and phonemes.
But I think we are talking apples and oranges here. I have not heard of Ph.D.'s, Th.D.'s, etc. with training in Semitic linguistics writing studies trying to paint speaking in tongues as false. i have not heard of missionary Bible translator linguists doing this. The Book 'Spoken by the Spirit' does relate an account of a missionary who was trying to figure out how to transliterate 'Jesus' into a target language in Africa, whether to go with a traditional pronunciation or something else, when, on furlough, he heard a message in tongues in that language which used the variant he was considering, and he decided to use that for the Bible translation.