According to UNESCO and other estimates, roughly half of the world’s 6,000–7,000 languages are in danger of disappearing within this century. Many among these languages are unwritten and only poorly documented. Therefore, researching and documenting such endangered languages is a linguistic prime objective.

In the Phonogrammarchiv, linguistic fieldwork on little-documented languages has played a major role from the outset. The advent of audio recording technology had made possible the sounding reproduction of spoken language, which added a new dimension to linguistic research and documentation. Thus, already in the first decade of the 20th century fieldwork took place in such remote areas as Papua New Guinea, Brazil, the Kalahari, or Greenland, using the Archiv-Phonograph developed at the Phonogrammarchiv. When magnetic tape recording devices became available, samples of Austrian dialects of German and other languages spoken in Austria were recorded nationwide in the 1950s and 1960s.

Today, the Phonogrammarchiv’s linguistic fieldwork makes use also of video recording, and research and documentation activities focus on a number of endangered West Himalayish languages of the district Kinnaur in the Indian State of Himachal Pradesh; they are spoken only in a handful of villages and were (re)discovered in the course of the Austrian Science Fund (FWF) project Documentation of Oral Traditions in Spiti and Upper Kinnaur (P15046). January 2019 saw the beginning of the cooperation project Corpus of Austrian Dialect Recordings from the 20th Century,  dedicated to audio recordings of Austrian dialects made in the 20th century.