耳栓
https://gyazo.com/58b6a61dc1324a2bdaa115867a3bb0e6
http://shimobayashi.hatenablog.com/entry/2012/12/14/耳栓を選ぶ
http://hitoriblog.com/?p=8744
https://www.amazon.co.jp/dp/B00CSJC6Q2/