On most devices, while playing content, select Audio & Subtitles . “English 5.1” = surround mix. “English Original” = stereo mix. Some titles also offer “English Atmos” (object-based).
A controlled ABX test was conducted with 20 listeners using three playback systems: high-end 5.1 (calibrated), soundbar with virtual surround, and stereo laptop speakers. netflix 5.1 audio vs original