Mine seems to vary / spike on its own schedule, not caused by anything or for there to be anything else to correlate it to for there to be a delay.
I went to a loud show and was fine afterwards. I woke up the next day and was still fine. But after 2 days had passed, the spike finally showed itself.
I believe delayed spikes usually take around 1-4 days to happen. But in some cases, they can occur up to 2 weeks later after the noise trigger.