This is the 366th most frequent Japanese word.
え
"え" means "picture" or "drawing" in English.
In this sentence, 'え' expresses surprise or a reaction to hearing something unexpected.
え、そうなの？
Huh, is that so?
'え' in this context functions as an indication of not hearing or understanding something fully.
え、聞こえなかった。もう一度言って。
Wait, I didn't catch that. Please say it again.
Here, 'えっと' is used as a filler word to indicate hesitation or thinking.