Which of the following describes a Geiger-Muller counter?

A Geiger-Muller counter is specifically designed to detect ionizing radiation, which includes alpha particles, beta particles, and gamma rays. This type of counter operates by using a Geiger-Muller tube filled with gas that becomes ionized when it interacts with radiation. When ionizing radiation passes through the tube, it produces ion pairs, which leads to a measurable current. This current is then converted into audio or visual signals, providing a means for users to quantify and interpret the level of radiation present in their environment.

The focus of this device is solely on its ability to detect radiation, making the option related to sound, shielding, or serving as a source of radiation irrelevant in the context of what a Geiger-Muller counter is and what its purpose is within radiation protection and monitoring. Understanding its primary function aids in appreciating its role in ensuring safety and compliance in environments where ionizing radiation is present.