One effective way is to feel that the sound is not coming from your larynx or your throat, but rather radiating outwards from your heart center or heart chakra (the energy center in the middle of your chest, near your physical heart).
An easy way to find your heart center is to point to yourself where you say “This is me.” Most people point to the middle of their chest. Close your eyes and hold your finger there and bring your awareness to where your finger is touching your chest. Then bring your awareness just behind that point, to the middle of your chest. Try to feel the sound emanating from that point.
It’s helpful to chant a sound that has had spiritual significance for millions of people over the years, whether a word from your own religious tradition, or the word Aum or Om, the most ancient of all mantras or sacred meditation sounds.
You can also meditate on a sound made by someone or something else, for example a Tibetan bowl or chime, by feeling it resonate inside your heart center. In my meditation classes, I use Flute Music for Meditation by Sri Chinmoy, because it’s beautiful peaceful music, and it’s unusual to find music created by one of the enlightened spiritual masters. Imagining that it is resonating inside your heart will help give you a deep and peaceful meditation.