NEW YORK ( MainStreet) -- If you're a job applicant -- even one with multiple opportunities on the table -- the clock is always ticking on that other side of the table.

There's an expiration date on any outreach from human resources personnel who call or email with either an offer for employment or an offer of a job interview.

Assurance Wireless, a Warren, N.J., telecommunications provider, has the goods on the patience (and impatience) of human resources staffers when it comes to contacting job applicants. The firm released a study this week showing, among other things, that if job applicants don't respond to an HR phone call within 48 hours, the company will pull any job offer or interview offer -- and they won't be calling back.

In the survey of 303 human resource professionals, 94% of human resources managers say they will "move on" to the next job candidate if their first candidate doesn't respond in a timely manner.

To get on hiring managers' good side, answering their phone calls within 24 hours is a must. If not, most managers begin to think you see their firm as a "Plan B" and will move on immediately to other applicants.

Past a quick response time, try these tips when HR calls:

Show passion. Hiring managers try to avoid job candidates who don't show any gumption (and yes, waiting two days to return an HR phone call shows a lack of gumption). Often, they will hire an applicant who show his or her passion for the job over a more qualified candidate who appears indifferent to the post.

Return the call via phone -- not text or email. While it's perfectly acceptable to text or email back and say you'll return an HR manager's phone call ASAP, don't return a call with a text saying "What's up?" or "Great -- I accept the job and can begin Monday." Hiring managers can be a sensitive lot, and they don't like it when the potential employee dictates the preferred method of communication.

Slow down -- and listen. Odds are that you're excited about working for a new company. When you do speak to an HR representative, take a deep breath, slow your speech patterns and listen closely to what the rep has to say. If you dominate the conversation, that can leave a bad impression, and you'll get plenty of chances to be heard on the job.

Most of all, do not leave that hiring manager hanging. If you get a call, whether you want the job or not, call back that business day if possible. Even if you don't want the job, HR people are a close-knit group, and you may develop a reputation in your industry as a prima donna who can't be bothered to return a phone call.

Sounds simple, right? But as the Assurance study shows, it's something HR professionals take very seriously -- and so should you.