noun
earmuffs; ear warmers
Specifically for protection against cold weather.
寒い日は耳あてをして出かけます。
On cold days, I go out wearing earmuffs.
子供に耳あてを買ってあげた。
I bought earmuffs for my child.
Loanword from English 'earmuff', often used for industrial or noise-reducing earmuffs rather than cold-weather ones.
Compound of 耳 (ear) and 当て (something applied or placed against).