Final answer:
Sound pressure levels are measured in decibels (dB) and the most accurate device for measurement is a sound level meter. The sound pressure level differs from the sound intensity level and is notably used in aquatic applications where decibel levels can be much higher.
Step-by-step explanation:
Sound pressure levels are typically measured in decibels (dB) and can most accurately be measured with a sound level meter. A sound level meter is a device that measures the intensity of sound at a given point, which can be translated into a sound pressure level. The sound pressure level is the ratio of the pressure amplitude of the sound wave to a reference pressure, which is typically the threshold of hearing at 1 kHz, defined as 20 micropascals in air.
It is important to understand that the sound pressure level is different from the sound intensity level, which is a more familiar concept for sounds in air. The sound pressure level is particularly important in applications where sound travels in water, such as studying ocean noise pollution, where the decibel levels may be significantly higher than those of sound intensity levels for the same sound in air.