Pilot reported a track deviation resulting from confusion regarding similar sounding fix names; JOENZ and JONEZ; while departing on the HROCK1 SID from FLL.

Narrative

We were climbing below 10000 ft. on the HROCK1 departure out of FLL. Miami departure gave us a heading; then direct to an intersection. As Pilot Monitoring I was working the radios and programming the FMGC. I believe the controller spelled the intersection out as JONEZ. I read it back spelling it out phonetically as JONEZ. The controller was busy and did not acknowledge or correct me; she already moved on to issuing instructions to other aircraft. I took that to mean the read back was correct and after confirming with the FO who was Pilot Flying I hit direct JONEZ. That intersection was also directly ahead of us so it seemed correct. After about 30 seconds the controller asked if we were direct to the intersection and I stated that we were. She answered that it didn't look like it; proceed direct HROCK intersection instead.While doing that I realized that there was a JOENZ intersection on the departure which was probably where we were supposed to have gone initially. We navigated to HROCK intersection and completed the departure uneventfully. To my hearing it sounded like the controller spelled the intersection out as JONEZ; though I could be wrong. If I had looked on the flight plan for the intersection I would have seen JOENZ instead of JONEZ and queried her. As it turned out I read JONEZ back phonetically and the controller either was too busy to correct me or believed I read it back correctly; so I typed it into the scratch pad and hit 'Direct to' after confirming with my FO who also agreed with the spelling. The fact that JONEZ was directly in front of us further added to the assumption that it was correct. In the future when being given clearance to an intersection; even if it's being spelled out; I'll quickly scroll through the flight plan to see if it is already on our route before simply typing it in.