A few years ago, the trend in television advertising seemed to be montage designed to turn my television into a strobe light. I imagine you could kill someone with epilepsy that way. Later the strategy shifted to the audio spectrum, with commercials anywhere from 10-30 dB louder than the content shoehorned into the airtime between them. The decibel blast is still part of the strategy, but more and more, the 'voice roll' is becoming an almost universal feature of television and radio advertising. Salient features include wildly exaggerated inflection, exaggerated difference between loud and less-loud syllables, sustained vowels on 'key' words, the sustained tempo of the hypnotist or preacher. The keyest of the key words are of course the phrase 'Call now!' There also seems to be a tendency to a mid-south accent; along the lines of the 'Tennessee trader' stereotype.
This style of vocal delivery has always of course been characteristic of a certain ghetto of the advertising world; the infomercials, and the types of products that associate with that crowd— the too-good-to-be-true propositions, and the sales pitches built around pressing people's inadequacy buttons. Then of course it spread to the characteristically salesy industries which until recently were doing the strobe light thing—replacement windows and furniture. Maybe it's just my imagination, but the practice seems to be spreading to a larger and larger portion of all TV and radio advertising. Almost all radio advertising, in fact. Perhaps these things go in cycles, and once again the emphasis will be on flashing lights and whooshing noises. There is of course a sort of arms race between advertisers and we the people with our time-shifters, popup-blockers, and recently my rapid-fire trigger finger on the mute button. STFU, folkx!