Aisi is a Trans New Guinea language spoken by a couple hundred people in Madang Province, Papua New Guinea. I visited Musak village for three weeks in January and February, 2012. I also worked with speakers in town in 2006 and 2014.
Magɨ, closely related to Aisi, is spoken in the village of Wanang. I visited Wanang for a couple days in May 2012. Linguists were not aware of this language until my visit, and by then it was only spoken by people middle-aged and older. Wanang also happens to host a biological field station belonging to the New Guinea Binatang Research Centre, and the villagers have created a rainforest conservation area!