Active noise cancellation reduces preferred listening volume, protecting hearing

Evidence

The Apple AirPods Pro 2 offers active hearing protection in transparency mode where the SPL during a concert or other loud event can be reduced by as much as 18 dB with better fidelity than a passive hearing protector. With transparency mode off background noise can be reduced up to 22–30 dB, which can lead to lower and safer preferred listening levels. These are examples where headphones prevent hearing loss instead of causing it. — Toole, Floyd E, Sound reproduction- the acoustics and…, 1707

Categorization

• ADDENDUM: Connects to the broader equipment-as-infrastructure theme; if headphones serve as hearing-protection infrastructure, there’s a tie to how tools become protective systems rather than hazards.