A stellar first impression during a job interview -- with components like a firm handshake, being well-articulated and showing enthusiasm for the job -- can clinch your chances for being hired.

But what if you have to impress that prospective employer over the phone?

Phone interviews are more common now, being used by companies as a quicker and cheaper tool to winnow the pool of job applicants, hiring and career services officials told us. Sometimes these interviews are planned, and other times, unfortunately, they're not.

Here's how to prep for a planned phone interview.

One critical thing to remember: These conversations, expected or not, are just as important as face-to-face interviews.

"They're screening interviews, generally, and it's either you're in or you're not," said Kathryn Wieland, director of business career services at Iowa State University's College of Business.

Cindy Lyness, owner and general manager of Management Recruiters of Cedar Rapids, Iowa, said the majority of initial interviews they schedule -- 65 percent to 75 percent -- take place over the phone.

Hearing an interviewee on the phone -- especially those applying for positions in sales, customer service or account management -- gives employers an idea of what a customer's first impression would sound like, Lyness said. "They want to hear the delivery."

Employers also want to see if the person is a good cultural fit for the company. "They just want to hear the candidate talk, to see if the interpersonal connection is there," Lyness said.

The greatest criticism Lyness hears from employers is that people sound tired and unenthusiastic.

Therein lies one big problem: how to convey interest strictly through your voice. As dreaded as a sit-down meeting can be, interviewees can take advantage of nonverbal communication.

"You really have to use an animated voice," Lyness said. Listen to the pitch and tempo of your speech. Speak loudly and clearly. Also if you need help, ask a friend or spouse to sit down and ask you questions, then try having that conversation on the phone and tape it.

Phone interviews have become so common that Iowa State University's College of Business incorporated the topic into one of its classes. Students learn how to be phone-savvy as part of an eight-week course called "Professional Employment Preparation."

Wieland reminds students to always have their "professional, job-seeking self" on the phone.

Prep yourself like you would for a face-to-face interview.

Remember, too, to get rid of slang, Lyness said. Don't say "um," or "you know."

Before the interview, make sure you find a quiet place and have your resume, the job description and a list of questions for the employer handy. If you're at your computer, you can have the company's Web site up but don't type while on the phone.

When you feel like the call is wrapping up, be decisive, Lyness said. Let the employer know specifically when you're able to meet personally. Say you'll be in town next week, or give specific days when you'll be available.

WorkBytes column written by and for Gen Xers learning the realities of the workplace. Dawn Sagario and Tim Higgins of The Des Moines Register take turns writing this column each week. Write the columnists at The Des Moines Register, P.O. Box 957, Des Moines, Iowa 50304-0957.