An interesting article about the “pop-punk voice”: “I made a linguistics professor listen to a Blink-182 song and analyze the accent”. The song is in the video above, and an excerpt from the article is below, although the whole thing’s worth reading:
Penelope Eckert, a linguistics professor at Stanford, is one of the foremost scholars examining what’s known as the “California Shift.” The California Shift is a linguistic theory covering the particular changes in dialect that affect the Pacific coast of the United States. Eckert was nice enough to humor me and listen several times to a song I chose based on its particularly egregious “pop-punk voice,” Blink-182’s “First Date.” I love the song, but am aware others may find it horribly annoying. “It really does sound like someone's messing around,” she told me. [...]
Eckert walked me through the Blink-182 song word by word, pointing out places where DeLonge was playing around with accent. “When they say ‘to pick you up on our very first date,’ the interesting thing about ‘date’ is that he renders it as a monophthong ‘dehhht’ instead of ‘date,’ says Eckert. “In most American English it's a diphthong.” A diphthong is a vowel sound with two simpler sounds in it; for most Americans, “date” is a kind of compound vowel made up of the “eh” sound and the “ee” sound. Not so much for Tom DeLonge, who eliminates all but the “eh,” making it a single sound, or a monophthong.