You mean talking like Paris Hilton won't land you a job?
This type of speech seemed to become popular around the time Paris Hilton became famous for being famous:
Vocal Fry May Undermine the Success of Young Women in the Labor MarketVocal fry is speech that is low pitched and creaky sounding, and is increasingly common among young American females. Some argue that vocal fry enhances speaker labor market perceptions while others argue that vocal fry is perceived negatively and can damage job prospects. In a large national sample of American adults we find that vocal fry is interpreted negatively. Relative to a normal speaking voice, young adult female voices exhibiting vocal fry are perceived as less competent, less educated, less trustworthy, less attractive, and less hirable. The negative perceptions of vocal fry are stronger for female voices relative to male voices. These results suggest that young American females should avoid using vocal fry speech in order to maximize labor market opportunities.
In my vintage charm books there are tutorials on how to have a pleasing voice (I don't have time to dig them out). In them, what we now refer to as "vocal fry" would be an example of how NOT to speak.
I learned early in my career that my voice, and not just my words, was a key to my success.
While working a seasonal job at L.L.Bean in my 20s I had a customer on the phone who questioned the information I was giving him despite the fact that what I relayed was company policy, verbatim. He asked to speak to my manager who is also male. When I put him on the phone with him I listened to what he told the customer. He repeated what I said, verbatim. The customer was satisfied.
I wondered, was it just the fact that he was a manager that appeased the customer? Maybe. But I reflected on the fact that my presentation was tentative. I wasn't exactly "uptalking" which is making statements as a question, but I wasn't a confident speaker, either. I resolved to work on my diction. I wanted to channel confidence. In time I noticed that more people, both men and women, seemed to take me more seriously. When we come across as uncertain of ourselves that's a cue for others to do the same.
Confidence isn't the same thing as being cocky, loud and boastful. It comes across as calm and assured. That doesn't mean people won't ask questions, but usually they are based upon the content of what you are saying and not the competence of the speaker.
I continue to work on my speech. I grew up in NYC but my accent faded over the years living in Maine, Vermont and in the south. I'm often told I speak "broadcast English." That makes me sad as I do like to have some flavor in my speech. When I get annoyed the NYC does creep back in. : )