The wearing of noise reducing ear plugs at night is very common, with people attempting to block out external sounds in a noisy environment (such as traffic noise) to a loudly snoring partner, the search for a good night's sleep is often a constant one.
While there is no inherent risk of hearing damage with the long term use of ear plugs, there may well be other possible side effects involving the ear canal.
The first possible issue is with the production and excretion of wax. A small amount of wax in the ear canals is a healthy position, as it keeps the ears clean and moist. Ears are self-cleaning and the wax works its own way out with normal washing and showering.
Continued use of ear plugs may interfere with the wax migration process and lead to a build-up of wax, which can cause temporary ear pain or dulled hearing.
The second possible consequence of continuous use of ear plugs is an increased risk of ear infection.
The ear canal is a warm and moist environment in which bacteria can rapidly grow. By keeping the ear canals open at night, natural ventilation helps prevent the build-up of such bacteria. Blocking the ear canals with ear plugs obviously prevents this natural ventilation, and so the risk of bacteria multiplying and leading to possible infection is increased.