Which of the following is illegal while driving?

  1. Wearing a headset or ear plugs that covers both ears. ✓
  2. Wearing a headset or ear plugs that covers one ear.
  3. Using cruise control on residential streets.

Answer: A. Wearing a headset or ear plugs that covers both ears.

Wearing a headset or ear plugs that covers both ears is illegal while driving.

Why this is the answer

The handbook's section on health and driving says hearing matters because you need to hear horns, sirens, motorcycles, and screeching tires that warn you of hazards. Right after that, it states plainly that wearing a headset or earplugs in both ears while driving is illegal. So the rule is about blocking both ears at once, which is the choice that matches the handbook's wording.

Why the other answers are wrong

Remember it

Both ears blocked is the line the handbook draws, so remember it as an all-or-nothing hearing rule.

Official handbook: California Driver Handbook (DL 600), Section 5: An Introduction to Driving, p. 9

Explanation drafted with AI (deepseek-flash) from the official handbook passage cited above, then checked automatically and by a second model on 2026-10-23. Always confirm with the official handbook.