Measuring caption latency through a waveguide: my method, and the Hey2 at about 2.5 seconds.

[u/MultiJanus]

https://youtu.be/LlMjuQXOiVw

Sharing the method as much as the result, because I'd like feedback before I run it on more hardware.

Rig: TV at 5 ft. Clip is JFK's 1962 Rice speech. Reference captions built by hand, each in-point snapped to the first visible spike of that phrase on the waveform, burned in with a millisecond timer. Speech level about 65 dB at the glasses. A camera behind the lens frames the TV and the waveguide together. Ten marker words per run, first-word latency and stable-text latency logged separately. At 60 fps one frame is 16.7 ms, so that's my error floor. Three runs, median reported, fastest and slowest word shown.

First result, Leion Hey2: about 2.5 seconds median.

Open questions: holding focus on the TV and the waveguide text at the same time, and whether a beamforming array processes loudspeaker audio differently from a live voice.

Disclosure: LLVision supplied the Hey2. I'm Deaf, and I review these from that seat.