Puppy socialization can also include making funny encounters and stupid sounds at puppies; revealing those to skateboards, bikes, wheelie bins and other moving things. Sounds of airplanes, loud machinery, children screaming, babies crying, radios blaring are usually everyday occurrences that your puppy may experience in later life. CD's can be found with all sorts of noises, including thunder which is something that is not always available for the doggie to get accustomed to.
Puppy preschool or kindergarten is a superb avenue for socialization with other pups of an identical age. However, the conflict comes from the question of doggy vaccinations "is it safe to have a puppy out during this time period?" This is a problem because on the main one hand you want to train your puppy to be sociable but keep the puppy safe at the same time.