Kou shrugged. "Loud. Most don't reduce background noise, rather it makes people turn up the volume. That gives you headaches and this is probably boring you," he said, hurrying the conversation and bringing it to a halt. Whenever he'd talked about safety he'd seen most people's eyes glaze over.
He looked at Kozue, "And you don't think she does, otherwise you wouldn't have worded it as a question."
He didn't know Kozue's grandmother, but she was an elder citizen of a good family. He'd been brought up to respect his elders.