Is it possible for someone to train in martial arts and be able to get the benefits of a Kihap, but be silent.
It depends on which benefits you’re asking about.
On the simple mechanical side, a kihap is a forced exhalation of breath from the lungs and the diaphram which results in a tightening of the muscles and protects the core. You can round up the passive benefits by studying martial arts and breathing, learning how timed intake and exhalation of oxygen can affect (both benefit and debilitate) your technique.
However, the other side of the kihap is the psychological benefits. The loud shout of the kihap can disrupt and scare an opponent, it builds confidence in the practitioner, and can help develop discipline. The kihap and it’s benefits is explained in depth here: Kihap Taekwondo’s Spirited Shout
The downside of the shout in most of it’s variations is that it can signal when you’re about to attack, which is where Bruce Lee developed his method of covering his breathing and shouts by making those now stereotypical and trademark noises that have become associated with Eastern martial arts in Hollywood cinema. He did it because it confused his opponents and preyed specifically on the expectations of other martial artists.
So, can you train in traditional martial arts and avoid the kihap, kiai, and the other variants? If the shout is part of the form of martial arts that the character is training in, then no. If it’s not, then they won’t use it but they also won’t get the benefits of it.
If what you’re saying is: I want to use this martial art but I don’t like kihaps because I think they’re silly then my answer is get over yourself.
-Michi
