I think that your safety headphones are a really great idea Mark. They would make life a lot safer and they can offer people a lot of comfort too, like a very safe and careful friend in your ear at all times. It's especially great that they will help you avoid noisy places so you can always find some peace and quiet. I can think of a lot of people that might need a bit of a hand in these situations, especially when crossing the road, don't you? Very well done, keep inventing!...