Wolves, like people, communicate in many ways. They use their voice, face, posture, hair, and tail as well as their senses of smell, touch, vision, and taste. Skilled communicators, wolves choose what they need to get their message across: during the day, for example, they may communicate with posture, but at night howling or other vocal signals may work better.
Howling, the most well known type of wolf communication, is an attention grabber. According to Fred Harrington and Cheryl Asa in"Wolves: Behavior, Ecology, and Conservation," howling can "instantly reach an audience from near to far at any time day or night." But much of the vocal communication between wolves is quieter, like the subtle sounds from pups in a dark den.
Pups are deaf at birth, start to hear by day 14, and by day 20 reach their adult hearing level. During those two deaf weeks, they moan, whine, squeal, and scream, but these sounds decrease as pups grow. By three to four weeks of age - when emerging from the den with adult level hearing - pups can make all the sounds of an adult and howl with the pack. But another six weeks must pass before a pup sounds like an adult.