The first LPSS was held in Academia Sinica in 2006 to specifically bring together scholars from linguistics and speech technology for discussions about what spontaneous speech is and how it can be understood and dealt with, given the common goal is to look for genuine linguistic patterns. In 2010, Kikuo Maekawa and Yasuharu Den hosted the second LPSS, as an Interspeech satellite event, embracing a prospective variety of research topics related to spontaneous speech and disfluency. Since 2014, the Institute of Linguistics, Academia Sinica (ILAS) and the National Institute for Japanese Language and Linguistics (NINJAL) have established bilateral collaborations. The collaboration project “Cross-linguistic research of the phonetic representations of filled pauses” has been successful in exchanging Chinese and Japanese data and research methodology on spontaneous speech. Given the fast-growing demands of intelligent technology systems involving the spoken language, the third LPSS in 2019 aims to explore application possibilities of spontaneous speech, including technology, pathology, and acquisition. Moreover, the organizers also hope to minimize the efforts that individual teams have to make by discussing the common theoretical and empirical works and by sharing data and know-how, with an integrative view.