Voice prompt recording
48 lines (12 new). Each line is checked against the delivery spec as you go: 8 kHz mono, peak −1 dBFS, ≤50 ms lead-in, 100–150 ms tail, under 4 s and 60 KB. Masters are kept at your mic's native rate.
1 · Room noise check
Stay silent for 3 seconds. The room should be below −50 dBFS; below −60 is ideal. This floor is also used to detect where your speech starts and ends.
— dBFS
2 · Reference voice
Each line has a "Hear reference" button (browser TTS, American English) and pronunciation notes. Match its pace and calm tone; do not imitate the robotic timbre.
Use a headset or external mic if you have one. Keep 10–15 cm from the mic, same distance for every line. Chrome gives live transcript checking; Safari/Firefox record fine without it.