This is the first time I've heard the Osaka dialect in quite some time.
I haven't heard anyone speak with an Osaka accent for a long time.
ーThis is the first time I've heard the Osaka dialect in quite some time.
「大阪弁聞いたの久しぶりだな」
This is the first time I've heard ... in quite some time. で「…を聞いたのは久しぶりです」
Osaka dialect で「大阪弁」
ーI haven't heard anyone speak with an Osaka accent for a long time.
「誰かが大阪弁を話すのを聞くのは久しぶりだな」
I haven't heard ... for a long time. で「…を聞いたのは久しぶりです」
Osaka accent で「大阪弁」とも言えます。
ご参考まで！
カナダ 
