When we pierce a balloon with a sharp needle, it pops and produce a great sound. But, It doesn't pop when we open the mouth of the balloon (through which we have blown air)…
So, Why doesn't the gas release slowly when we pierce it with a needle. In fact, it is released slowly when we release the mouth.
Best Answer
The difference between the "mouth hole" and the "needle hole" is that the mouth hole is reinforced and under low tension, while the needle hole is not reinforced and under high tension.
The mouth piece of a balloon, some might call it the "neck" of the balloon, generally includes a rolled section of material. This section is what I call it being "reinforced," since it is stronger than the rest of the balloon. Additionally, the neck is under low tension compared to the stretched fabric of the rest of the balloon.
So, why should any of that matter?
The tension on the surface of the balloon determines the response the balloon material will provide under a given load. When you poke a hole in, or open, the neck, not very much happens, because there is low tension (low force). However, when you poke a hole in the body of the balloon, the much higher tension there provides a larger response.
You can make an analogy to a stretched rubber band. If you stretch it a small amount, it is easy to perturb the rubber band a great distance. However, if the rubber band is stretched to near breaking, then even a small perturbation results in a snapping of the material, and the subsequent release of energy (both in motion of the pieces and in generation of sound).