The traditional way to place a Go stone is to first take one from the bowl, gripping it between the index and middle fingers, with the middle finger on top, and then placing it directly on the desired intersection. It is considered respectful of the opponent to place the first stone to the player's upper right-hand corner. Although it can be soothing and pleasant to run one's hand through the bowl or hold a handful of stones, this can be noisy and unnerving to one's opponent; it is considered good form to take only one stone at a time as one decides where to play. It is permissible to strike the board firmly to produce a sharp click. Many consider the acoustic properties of the board to be quite important. The traditional floor goban usually has a pyramidical hollow called a heso carved into its underside. Tradition holds that this is to give a better resonance to the click of the stones, but the more mundane explanation is it allows the board to expand and contract in varying conditions without splitting the wood.