Signal noise refers to any unwanted or irrelevant information that interferes with the clarity of a desired signal. In communication systems, this noise can distort the original message, making it difficult to understand. It can come from various sources, such as electronic devices, environmental factors, or even human error. In the context of audio signals, for example, background sounds like static or hum can obscure the main audio, making it hard to hear the intended content. Similarly, in data transmission, noise can lead to errors in the information being sent, requiring additional measures to ensure accurate communication.