It sounds like unbiblical nonsense. NDE's are demonic in origin. People who have them almost always describe going to Heaven regardless of their spiritual condition. They're deceived about their actual spiritual condition.

Tongues are another word for languages. It's clear from scripture that they're languages.

(Acts 2:4-11 NIV) All of them were filled with the Holy Spirit and began to speak in other tongues as the Spirit enabled them. {5} Now there were staying in Jerusalem God-fearing Jews from every nation under heaven. {6} When they heard this sound, a crowd came together in bewilderment, because each one heard them speaking in his own language. {7} Utterly amazed, they asked: "Are not all these men who are speaking Galileans? {8} Then how is it that each of us hears them in his own native language? {9} Parthians, Medes and Elamites; residents of Mesopotamia, Judea and Cappadocia, Pontus and Asia, {10} Phrygia and Pamphylia, Egypt and the parts of Libya near Cyrene; visitors from Rome {11} (both Jews and converts to Judaism); Cretans and Arabs--we hear them declaring the wonders of God in our own tongues!"