Voicing is one of the most critical aspects of piano maintenance and repair and perhaps the most mysterious. It’s mysterious because there is so little you can actually specify, unlike the precise measurements of key dip or let off.
Voicing is often referred to as “tone regulating” which has a more clear meaning. It is the technique of adjusting the various parameters that affect the tone of the piano. This of course includes regulation of the action and tuning. But most people consider voicing to be the manipulation of the density of the felt of the piano hammer. It is the image of the technician jabbing a tool with needles into each hammer.
A piano hammer is made of dense felt glued to the wooden hammer molding under extreme pressure. Voicing of a well made hammer (more on juicing later) mostly means slowly decreasing the tension and density by, yes, jabbing it with needles. However, it also means making the shape of the hammer correct, and in my opinion most importantly, making sure the hammer strikes all 3 strings of the unison at exactly the same time. It is only after all the other aspects affecting tone have been adjusted can you start doing something destructive like needling.
Most people approach piano maintenance like their dental work; they wait until something is wrong or broken. A high end piano will benefit much more from regular and incremental maintenance and ideally the technician you have taking care of your fine piano will approach it this way; doing a little regulation and voicing every time he or she tunes so there never is a big problem. You’ll also get much more pleasure for a longer time out of your piano. Piano tone, like tuning, degrades very slowly. So slowly that you don’t really notice it until something, like that twangy note in the treble or the fact that things don’t repeat the way they used to, jump out at you. When a piano is brought back to tonal shape after a long decline, the reasons you fell in love with the piano in the first place often come rushing back. “How did I put up with the way it was sounding” is often the lament.
Remember, we talking high end pianos here. A concert piano is continously maintained, ideally tuned every week whether it is played or not and I’d like to encourage you owners of concert level pianos to consider the same. Ok, maybe every week is too much, but every 6 weeks shouldn’t be and your tuner should work out a special pricing arrangement for you. In the process, voicing and regulation can be kept at near factory levels…ah bliss.