When DD was tiny my mum came over (rare event) and I put DD down for a nap and then sat in kitchen talking. My mum was laughing and talking loudly whereas I was creaping about and whispering. After one loud laugh I heard DD whimpering and I told mum if she didn't keep her voice down I would smack her bottom.
She looked affronted and told me not to let DD sleep in absolute silence and that it would be a rod for my own back.
I cringe to this day and wonder why I threatened to smack her bottom!