No you cannot it is impossible to produce two different sounds from your mouth at the same time.
Planes make the same sounds whether in the day time or night time.
Since it is an electronic instrument, it becomes an investment over time, you can use to produce many different sounds with the same device, and it takes less space than having several instruments in the same room.
you can put a pice of cake in your mouth then put a pice of pie in your mouth then /
You can't.
No. All modern synthesizers have MIDI, but most can produce many different sounds at the same time without any other MIDI device connected.
they produce a Siamese twins
yes, but it is very hard
No, your breathing in and out is controlled by your diaphragm which does not move in two directions at the same time.
say chippewa sucking in air through your mouth at the same time.
The sound that is produced by an Opera Singer is a pleasant open, warm sounding voice. Some singer have the ability to produce a very relaxing sound to the ears. This requires years of training. Opera singers have powerful sounds and at the same time, soft and Serene sounds if trained properly.
sounds
It is possible.