Whispers are sensory structures that help a cat gather information about objects and activity in its environment and probably play some role in hunting prey. Whispers may aid scent detection by directing air currents to the cat's nose and mouth. Whisper position may also be part of intraspecies communication, but I'm not sure since I'm not an expert in cat behavior.
Feline whiskers, also known by its latin name "vibrissae" which means: hair on the face or nostrils of most animals, are required as sensors.
The Whiskers help to guide and assist the feline by sensing their way around the environment.The Cats whiskers are extremely sensitive, which helps make them better hunters. It helps them with their balance and guide the way around darkness. The whiskers also sense air currents and vibrations, and to tell the distance of an object or its prey.
Having said that, cats can also smell over 200 million different scents.