Hearing aid tubing carries sound from the earhook to the earmold, which directs sound into the ear canal (among other functions). Standard tubing comes in a variety of sizes, with size 13 being the most common. Some tubing is clear, which will yellow with time. Other tubing is flesh-colored (see Figure 2). Regardless of color, new tubing should be flexible. One of the signs that it is time to change the tubing is when it becomes hard and brittle.
The first step in changing hearing aid tubing is to detach the tubing from the earhook, leaving just the tube and earmold (see Figure 1). Next, the old tubing needs to be removed from the earmold. This can typically be accomplished by simply pulling firmly, but it is sometimes necessary to use a reamer. A reamer (see Figure 2) is a small, drill-like tool that is used to bore out tubing that is stuck in an earmold. Once the old tubing is removed, keep it nearby because you will need it when trimming the new tubing.
New tubing has a tapered end, that makes it easier to pull through the earmold. A tubing puller (see Figure 2), consisting of a thin loop of plastic or wire attached to a handle, is passed through the sound bore of the earmold. The tapered end of the new tubing is placed in the loop protruding through the back of the earmold. Then the tubing puller is pulled back out of the earmold, taking the tubing with it. Figure 1 shows a brief animation of this process.
After the new tubing is in place, the tapered end should be trimmed until flush with the sound bore. The next step is to trim the end of the tubing that will attach to the earhook. Using the old tubing as a guide, trim the new tubing so that it matches the length of the old tubing. Finally, push the tubing onto the earhook and the process is finished!