 basically are herders, and they live in the Sudan, and they're just in an incredibly quiet environment. There's just no industry around them. They're not listening to loud music. They don't use firearms, those types of things. They're not exposed to noise. They're not exposed to toxins. They're not exposed to things that may damage their hearing, like certain medications and so on. And when they test them in their advancing years, they see some decline in hearing, but it's pretty minimal.