Bose has started an Indigogo campaign for prototype testing of their new noise-masking sleepbuds. These sleepbuds are ultra-compact earbuds which isolate external noise and play soothing nature sounds to aid in achieving a good night's sleep.
https://www.notebookcheck.net/Bose-wants-to-improve-your-sleep-with-noise-masking-sleepbuds.263970.0.html
I don't see any pressure relieve hole... maybe after few years of usage, people will begin to complain about hearing loss or worse people might die in accident because they are still sleeping, this is the same tech before Hush was acquired by Bose https://youtu.be/QN9sAMA2eIc?t=40s