Final answer:
The Bell Labs engineers known for establishing the equal loudness contours of the human ear are Harvey Fletcher and Wilden A. Munson, who developed the Fletcher-Munson curves.
Step-by-step explanation:
The Bell Labs engineers who established the equal loudness contours of the human ear are not mentioned in the provided information. The correct individuals associated with the discovery of equal-loudness contours are Harvey Fletcher and Wilden A. Munson. Their research in the early 1930s led to the creation of the Fletcher-Munson curves, which are a fundamental concept in the field of psychoacoustics, illustrating how the perceived loudness of sounds varies with frequency and sound pressure level.
Oftentimes, information confusion might occur due to the multitude of discoveries attributed to Bell Labs engineers. It's important to note that while Robert Wilson and Arno Penzias, mentioned in the provided figures, are Nobel Prize-winning scientists, they are known for their discovery of the cosmic background radiation, not for work related to the equal-loudness contours.