Vocal fry

Vocal fry, or glottalization, is a low, staccato vibration during speech, produced by a slow fluttering of the vocal  chords: listen here  http://news.sciencemag.org/sciencenow/vocalfryshort.mp3

According to Science Now:

"A curious vocal pattern has crept into the speech of young adult women who speak American English: low, creaky vibrations, also called vocal fry. Pop singers, such as Britney Spears, slip vocal fry into their music as a way to reach low notes and add style. Now, a new study of young women in New York state shows that the same guttural vibration—once considered a speech disorder—has become a language fad.


Since the 1960s, vocal fry has been recognized as the lowest of the three vocal registers, which also include falsetto and modal—the usual speaking register."


Here's a full blown example: http://grammar.quickanddirtytips.com/