When my oldest was little we had a clock that chimed every half hour. It was a deep tone best imitated by saying "dong-dong". She used "dong-dong" to refer to not just that clock but every clock and wristwatches too.

We went out to eat where there happened to be a chiming clock on the mantel. After it stopped she sat thinking for a minute and then asked loudly, "Daddy where your dong-dong?" We knew she meant his wristwatch but we got some really funny looks. LOL

Am picturing some little one staring at Ben and wondering where his dong-dong is.