Inside our ears, there are tiny things called inner hair cells that help us hear by changing sounds into signals that go to our brain. When these cells get tickled by sound, they send messages that let us know what we are hearing, like music or voices.
A train warning is a signal that lets people know a train is coming, so they can stay safe and not get too close. It can be a sound like a whistle or bell, or a light that flashes to tell everyone to be careful.
Signal communication in animals involves using signals or cues to convey information between individuals, facilitating various forms of social interaction like mating, warning of danger, or establishing territory. These signals can be visual, auditory, chemical, or tactile, and are integral to an animal's survival and reproduction by enabling them to coordinate behaviors and make adaptive decisions.