As if tackling business development, sales and the raising of capital were not hard enough, researchers have found one more challenge for entrepreneurs to worry about: the sound of their voice! 

In March, University of Glasgow researchers Phil McAleer and Pascal Belin, along with Princeton University researcher Alexander Todorov, published a study after testing how the sound of people’s voices affected those listening to the communication: They concluded, “On hearing a novel voice, listeners readily form personality impressions of that speaker. Accurate or not, these impressions are known to affect subsequent interactions.”

And a 2012 study by Quantified Impressions found that the sound of a person's voice is twice as important as what the individual is saying. This means that no matter how well crafted the message, the wrong sound could kill a deal.

Related: Sound Advice: How to Make Your Voice More Effective

As Irv Shapiro, CEO at Ifbyphone, a voice-based marketing automation company, wrote in Marketing Profs in February, “in today's digital world, the roles that the human voice and the phone call play in marketing and sales success have never been bigger. Calls have re-emerged as the most effective channel for generating high-quality leads and closing business.”

Indeed, ask people their opinion of their voice and most will respond along a spectrum that includes harsh self-assessments such as "I don't like it" or "I can't stand it." 

Entrepreneurs can spend considerable amounts of time working on how they look and the way they work and think. But most have not given any serious thought to how they sound and if any changes may be needed to improve their business prospects.

And people judge others -- in some cases very harshly -- based upon how they sound. As Jayne Latz, president of Corporate Speech Solutions, told KPCC's AirTalk, "People are absolutely judged by how they sound." Latz stressed that just as professionals must learn how to dress for success, they should learn to use their voice for the best outcome.

Entrepreneurs should be concerned by voices that are rough, raspy, weak, strained or breathy. Listeners consider these qualities unappealing and they may have an adverse effect.

Related: Your Tone of Voice Can Boost or Bruise Your Personal Brand

Some argue that in the age of social media, face-to-face interaction is less critical and the sound of a voice less important. But the reality is that social media and other Internet-based applications are merely tools that may be ultimately leveraged for the purpose of arranging face-to-face or telephone meetings.

“Nothing will replace face-to-face," Joyce McKee, CEO of Let’s Talk Trade Shows, contended in a 2012 publication of Meeting Professionals International. "Yes, social media can augment it but … dots are connected on the trade show floor. Inspiration is born on the trade show floor.”

Given that so much entrepreneurial energy is spent communicating on the phone or face-to-face, it seems logical that entrepreneurs spend an appropriate amount of time to analyze their voice. Joseph Love, creator of Sing for Success, told me in an interview that he believes that "every businessperson should record their voice to find trouble spots." 

Love encourages entrepreneurs with voice deficiencies to seek the assistance of a voice professional. While some issues are physical or health related, voice coaches can in many cases provide quick and affordable remedies such as exercises and other strategies to improve the sound.

At a minimum that entrepreneurs should record their voice, listen for trouble spots and look for insights online, he suggested. 

Based upon the importance that voice plays in business transactions, entrepreneurs should find it in their best interest to analyze their voice to ensure it works for them as an asset -- and isn't a liabilty.

Related: Petrified of Public Speaking? Keep These Tips and Your Audience's Fears in Mind