Sounds are vibrations that travel through the air or other mediums, creating waves that our ears can detect. These vibrations can come from various sources, such as musical instruments, voices, or natural phenomena like thunder. When these waves reach our ears, they are converted into signals that our brain interprets as different sounds. The characteristics of sound include pitch, loudness, and timbre. Pitch refers to how high or low a sound is, while loudness describes its intensity. Timbre is what makes a sound unique, allowing us to distinguish between different sources, like a piano and a guitar, even if they play the same note.