The traditional focuses of sociology include social stratification, social class, social mobility, religion, secularization, law, sexuality and deviance.
These were called calceus mulleus, and the name may have been shortened to mules by English speakers. Hence the primary difference between mules and clogs in early days was that clogs were likely to be worn by working people, and mules were fancier and favored by the aristocracy.
edit Sound. Every mule has a unique bray that is a combination of the horse's whinny and the grunting of the wind-down of a bray. Most mules start out Whinee..... like a horse and end in-aw ah aw like a donkey.