Bone conduction – it may sound slightly unpleasant on first hearing, perhaps something akin to the reported practice of the ancient Scythians of drinking from the skulls of their enemies, but it is, in fact, a very clever method of delivering sound straight to your cochlea whilst cutting out all that messy ear canal/eardrum nonsense.
The ‘tech’ behind sensing sound through the bones of the skull actually dates back to the 15th century (in a way) and was in fact how famed German ivory tickler Ludvig van Beethoven managed to keep playing the piano once he lost his hearing. However, despite old LvB being able to keep pumping out tune after tune, it wasn’t until 2008, 181 years after Ludy’s death that the first bone conduction headphones went on sale.
