Method

Shi Sheng 试声

shì shēng

“Testing the voice” — issuing voice and force in the same instant, so as to reinforce Fa Li reflexively. The sound comes from within (from the belly and diaphragm), not as a shout at the opponent (Wang: “like a voice in a silent valley, like a bronze bell”). Two sounds are used — “Yi” and “You/Yao” — in three stages: (1) each separately, hoarse and muffled; (2) joined (Yi-You Tong Sheng, “as if a great stone fell into a well”); (3) with no audible sound — only intent and force.

A sound from within, not a battle cry

Shi Sheng literally means testing the voice. It means issuing voice and force in the same instant. Yao Chengguang puts it in one sentence: “When your intention arrives, force arrives — and voice.” The sound is therefore not an addition to Fa Li but its audible side.

Wang Xiangzhai describes how it should sound: “like a voice in a silent valley, like a bronze bell”. That is the opposite of a battle cry. The sound comes from belly and diaphragm, not from the throat, and it carries because the whole body stands behind it. A saying of the tradition draws the line: a sound that is merely shouted is thin and empty.

Two sounds

“Yi” (咦) on the in-breath: the belly draws in, the breath rises. The image that goes with it: the forearms are lifted at the elbows.
“You” or “Yao” (哟) on the out-breath: the belly swells forward, the breath sinks into the lower abdomen — “like a stone falling into a well”. Inside there is a feeling of falling.

Both sound hoarse and muffled, not bright. How you know it is right: the sound starts in the same moment as the tension in belly and back and the pressure of the rear foot into the ground — not before and not after.

Three stages

1. Separately. “Yi” and “You” apart, each sound about two seconds. 2. Joined (Yi You Tong Sheng). Both sounds directly one after the other, together about one second. 3. Without sound. The sounds are taken inside: intent and force remain, the audible sound disappears. The test is a candle close to the mouth — with the silent “You” the flame must not flicker.

The third stage shows what this is about. The sound is an aid that gathers the release of force until the release no longer needs it.

What it is for

Gathering the force. The sound forces breath, trunk and legs into one shared moment. Where they come apart, you can hear it.
Taking a hit. The same sudden tension of the trunk also protects when receiving a blow.
Startling the opponent. A sudden sound can unsettle the opponent — a side effect, not the purpose.

Two rules belong with it: release at once after the burst (一发即止), so the body is ready for the next movement, and practise mostly soft, with only a few hard bursts (松多紧少).

Common mistakes

Shouting instead of sounding. The sound comes from the throat and turns loud and bright. It should be muffled and come from below.
Clamping the diaphragm. Holding the diaphragm hard during the burst is, according to the tradition, explicitly wrong.
Sound and force come apart. First the sound, then the movement, or the other way round. Then the sound is just noise.
Not releasing. After the burst the tension stays in place instead of going straight back into relaxation.

Where Shi Sheng sits in training

Here the sources diverge. With Wang Xiangzhai and Yao Zongxun, Shi Sheng stands right beside Shili, that is early, as a companion exercise to testing force. In Yao Chengguang's curriculum it comes only after Tuishou, as the second-to-last step before Sanshou.

Most likely this is not a contradiction in substance but one of teaching order: the principle belongs with Shili, but the method is introduced only once Zhan Zhuang, Shili, Mocabu and Fa Li hold.