People often mimic machine sounds by mouth, but some make a specialty out of reproducing the sounds of musical instruments. People who play with mouth noises are often inspired to imitate the trumpet. Some make trumpet sounds for simple amusement, but others practice to perform songs by mouth trumpet. Some of these well-practiced musicians have shared their secrets for making mock trumpet sounds by mouth, so that others may learn for any purpose.
Sing or hum the notes you wish to use for the mock trumpet sounds. Part of the sound resonates through the sinus cavities just as it does when you sing.
Press your lips together leaving a small gap in one corner of your mouth. Blow the air, and sound out through this gap as you sing the notes to imitate the trumpet.
Press your tongue against the roof of your mouth and vibrate it to make the sound of a rolling "R" as it is pronounced in the Spanish or French languages. Add the vibrating tongue noise to the notes you hum and press through your lips to make trumpet sounds.