How can you project your voice during a presentation without shouting?

Yes, 100%. And also take a deep breathe before you start. This helps your body physically relax and help takes tension out of your upper body.

I agree with this completely. Such a powerful insight. It's always to the speakers advantage to go prepared and ready. This will also boost their Self-confident

Too often, especially in a debate or an argument, society assumes the loudest person in the room is always right. To me though, the second you start screaming and shouting and clapping your hand you’ve lost the argument and frankly look embarrassing. Instead, Understand that standing up straight, slightly, puffing out your chest and slightly elevating your chin allows as much oxygen into your body as possible. Standing like this also engages the diaphragm, allowing your voice to travel confidently and loudly without the need to appear unhinged. When you engage your diaphragm and speak like this, you also appear to be a confident, grounded, and well prepared speaker.

I always think about the back of the room, and visualize pushing my voice towards the people furthest away from me. Sounds silly, but it's very effective in bringing breath up from the diaphragm to project. Remember, you're not yelling loudly, you're projecting strongly.

It’s important to learn how to correctly breathe for good voice projection, preventing strain and delivering with a warm, rich tone. To do that you should be breathing through your nose, deep into your belly, filling it like a balloon. As you speak the air is gently released through your mouth, vibrating your vocal cords along the way. Breathing should feel effortless and easy - if not, it may be worth getting some help to correct it.

Definitely watch out for proper enunciation of words - this will help your audience better understand and pay attention to what you are saying, especially if they have a different native language than you. It will also help you stay on pace, without speeding up to quickly.

To ensure good articulation it is worth doing a short vocal warm up that includes getting your articulates working. Lip trills (raspberries), stretching your tongue, massaging your jaw, humming and tongue twisters can all be used to ensure you’re ready to crisply articulate your words.

This is HUGE. For accessibility's sake, please, please: Use the microphone if it's available. You may enunciate well, have a louder voice, a nice, clear tone, but it's better to assume that someone in the audience will appreciate you using the microphone. With that in mind, try to test out the microphone ahead of speaking. Some are very sensitive and may need adjusting. Maybe all the microphone needs are some new batteries! If you have a lapel mic, you'll want to be sure it's not brushing on your clothes and causing feedback or other audio issues.

In my experience of listening to others, they start well, but often don't maintain the same level of projection throughout their entire time talking. I used to talk a lot to groups of elderly people and commonly, they thanked me for speaking loudly and clearly through out the entire presentation. They'd then tell me about all the others who didn't! :) A great way to ensure you maintain the same level of projection, is if you have notes - make a note for yourself to remind you as you speak. If you don't have notes, then write a sticky note and place it on the rostrum to remind you. Works a treat!

You can also solicit feedback from your audience - asking if everyone can hear you, checking for understanding, making sure that people are comfortable asking you to speak up or slow down, etc.

Related to the previous point about adjusting to the space, if at all possible rehearse in the room that you will be presenting in, with the help of a friend or colleague who can provide feedback on how your voice is carrying throughout the space.

Warming your voice up on the day of the presentation is important and can make a difference but I would suggest that you practice vocal exercises regularly to broaden your range (pitch and melody), improve your breathing and develop a more rounded, richer tone. This regular work will ensure you become more aware of your voice and be able to control it better, infusing more variety and interest with it during your speaking engagements.

Sometimes silence works best. Survey your audience for a few seconds before speaking further. You will grab their attention with a few seconds of silence.