I was camping in west Wales (UK) in summer and there were some really odd sounds coming in off the sea. The sounds were not audibly ‘loud’; you could here them but they sounded like they were a long way off. What was strange was that they ‘hurt’ the eardrum and could be felt in the chest. I speculated that it was big guns or something. But I’ve no idea really. Does anyone know what this could be? The internet is particularly unhelpful.