Last week, I went out to eat and had a flashback to my college Fundamentals of Communications class.

After telling my server my order, he unenthusiastically repeated my order back and incoherently muttered, “Ya-wan-ha-o-mile-o- fiya?” “I’m sorry,” I said, after staring blankly at him for a moment. “Do I WHAT?” He smiled sheepishly and clearly said, “Do you want hot or mild or fire,” referring to the sauce that comes with my food.

“Remember,” my Communications professor would say at the beginning and end of every class, “The first step to engaging your audience is using your words.” This guy clearly didn’t get it and, I admit, sometimes I’m guilty of rushing through a voicemail, or stumbling over my words in a meeting.

But the fact is, when you don’t speak clearly, the person or people you’re talking to can’t understand you. And mumbling not only makes you look silly, it ruins your credibility. And I’m not the only one who thinks so. Fuel Net: Marketing Smarts for the Growing Business blog had this to say about enunciating when communicating with your customers and prospects:

“One of the biggest mistakes that salespeople make when speaking to clients is talking too fast,” says Julian Blee, owner of Fat Cat Ideas, a company specializing in telesales training. Though this is understandable given the pressure of a sales call, clients will have a difficult time processing your message if you speak too quickly. Given that the average sales pitch is delivered at approximately 230 words per minute (WPM), significantly more than the optimal 180 WPM, Blee recommends these two steps to slow your rate of speech during sales calls:

1. Determine your normal WPM rate. Time yourself when reading something aloud. A book or newspaper will suffice, but the optimal solution would be to read your telephone sales pitch. Ensure that this is delivered in the same speed and style that you would use when speaking to a client over the phone. After 60 seconds, stop and count the number of words read to determine your WPM.

2. Optimize your WPM rate. To reach the optimum WPM of 180 words, find or write a paragraph of 180 words and practice reading it in 60 seconds. Once you’ve reliably achieved this WPM in practice, start attempting it during your sales calls while under pressure.

“This is not an easy thing to do,” Blee warns. “Our natural default setting is to speed up when stressed.” Speaking at a rate of 180 WPM is a skill that must be practiced and monitored before it becomes second nature. Once mastered, Blee says, this skill will prove invaluable in making you a better salesperson and conversationalist, both over the phone and in person.

So before you speak with a client or customer, give a presentation, or even take someone’s order in a restaurant, practice delivering your message clearly. You’ll feel more confident and your audience will respond positively.