It would be helpful to know which models of the yealink and what firmware. Phones re-register all the time and I don't really recall ever hearing anything like a beep or other sound to signify the re-registration.
Do they all beep at the same time or does each seem to beep independently of the others, but at the reported 10 minute interval?
If an extension is off-hook (in use) does it still beep?
Many phones have an option whereby they may beep in the event that there is voice mail pending retrieval. This allows those who might be sight impaired to know that voice mails are pending review. It also tends to force folks to manage their Vmail.
There were some reports about certain Yealinks exhibiting a beeping issue that was reportedly addressed by firmware. However, these were not being reported at occurring on any set interval, but completely random and ma have gone days or weeks between episodes.