密閉 みっぺい がたヘッドホンじゃありませんでした
mippeigata heddohonjārimasendeshita

Noun
Desu Copula

The polite, past negative form of 密閉型ヘッドホン

1. Were not closed-back headphones.; Were not sealed headphones.

Past/Perfective
Negative
Polite
Terminal Form