The following video will explain how we can use and train ourselves to make use of the nasal cavity when we sing. Though this videos primarily targets female singers, the lesson however will benefit the male singers as well.
My chorus has greatly improved their way of singing and even has produced a louder and fuller sound using the nasal cavity. It has diminished the strain off their vocal chords, enhanced their breathing pattern, and produced a sweeter and melodious sound fit for a choral group.
One way to force our selves to make us of the nasal cavity is by holding our noses. When we do this, it forces our mouth to open wider for air to pass through and in turn make use of this air to support the production of sound in the process.
Our mouth, the palates, tongue and our nasal cavity will then perform their function in supporting your voice in producing the sound.
Most of the time the vowel sounds, particularly the "ah" (A), will be more round and full when we make us of this technique.
After several rehearsals using this technique, your body will be accustomed to the way you sing and will no longer require yourself to cover your noses just to make use of your nasal cavity.
Again, practice makes it permanent.