Mainstream Kenyah, also known as Usun Apau and Bakung, is a Kenyah dialect cluster of North Kalimantan, Indonesia, and Sarawak, Malaysia. Dialects fall into four clusters:

• Lepo’ Tau, Lepo’ Bem, Uma’ Jalan, Uma’ Tukung^[2]
• Lepo’ Ke, Lepo’ Kuda
• Lepo’ Maut, Lepo’ Ndang, Badeng (Madang)^[3]
• Bakung, Lepo’ Tepu’ (Lepo Teppu’).

Phonology

Consonants

• Sounds /p, t̪/ can also occur as geminated [pː,  t̪ː] or as unreleased in word-final [p̚, t̪̚].

Vowels

• /i/ can also occur as lax [ɪ].
• Sounds /a, u/ can also be heard as long [aː, uː].^[4]