What instrument is commonly used for measuring sound?

The commonly used instrument for measuring sound is a microphone. Microphones are designed to convert sound waves into electrical signals, allowing for the measurement and analysis of sound intensity, frequency, and other acoustic properties. They are essential in various applications, from recording and broadcasting to sound engineering and scientific research.

In contrast, oscilloscopes, while they can display sound signals visually, are typically used for examining electrical signals rather than measuring sound directly. Rulers are physical measurement tools that quantify length but are not applicable for sound measurement. Thermometers measure temperature and, therefore, do not relate to sound measurements.