UPDATE: Bose has discontinued this product.
Bose recently released an alternative to earplugs. Their noise-masking sleepbuds block off an unwanted noise with an ambient sound (comes with an app). The buds fit in-ear but sit outside the ear canal, yet they should not cause any discomfort, even when you sleep on your side.
Apart from the soothing sound, Bose installed an alarm function. It is a perfect solution when you wake up earlier than your partner, as only you will hear the wake-up call.