Given the task of recreating an existing science or technology related project, we turned to the San Francisco-based interactive museum, the Exploratorium. We were fascinated by one project in particular, called the Vocal Visualizer, which uses your voice to turn laser light into patterns (check out the original DIY here). Since our objective was to make use of a DIY tool for “seeing” or “showing” the environment differently, we knew this project has promise. In order to make things more interesting, we decided to build two of the Vocal Visualizer tools and what happened when we had two people use them at the same time. When in use, we could see a projection of the sound as the balloon vibrated and reflected the pressure waves. The result was an experience similar to a Lissajous pattern — without all the complex equations.

Our Findings

Once the two Vocal Visualizers were assembled, we began testing how they worked with conversations between two people. We tried talking, yelling, singing, and humming, with different results for each. We projected the lasers on walls, and even on each other. The more we used the tools, the more people began telling us about their experiences as they watched and participated. They noted how the patterns were more spread out when people made random noises. Whereas when they laughed, the patterns fluctuated more. People said that this made them realize how brief laughing spells were, since the lasers were more fluctuating. We also found that deeper voices were more effective in spreading light. This was particularly interesting since we noted how deep, bellowing voices not only took up more air space in the room, but also the laser reflections took up more physical space. One participant noted that this made them realize when they are projecting their voice or when they are not. Another user noted that the pattern of the light actually mimics the way your mouth moves. And finally, someone said that this tool allows you to tell when you are singing well based on the fluctuating of the lasers. People were interested in the Vocal Visualizer when they saw it in use by itself, but what really brought out the discovery and fascination was when two people were interacting with each other using the visualizers to truly “see” what their conversation looked like. Each interaction was unique, because each person is unique. A conversation between two friends could contain a lot of fluctuating light from laughter, where as a conversation from strangers would reflect smaller light patterns. Visualizing voices allowed us to not only think about sound differently, it also changed the way we thought about our interactions with other people.

Step 1: Tools & Materials

Tools:

Measuring tape with both English and metric units
PVC cutter
Scissors
Double-sided tape

Materials:

Red laser pen/pointer with low power output; we recommend the common variety that is about 9/16 inches (14 millimeters) in diameter, about the thickness of your pinky finger (can be found at your local pet store)
Rubber bands
11-inch diameter balloon
2 Small plastic mirror
Various lengths of PVC pipe (1/2 inch, Schedule 40):
- One 6-foot (2 meter) length of pipe
- Two 1/2-inch diameter “elbows”
- Three 1/2-inch diameter T-joints
- 3-inch diameter solid, smooth-walled drain pipe, cut to a 4-inch length

Step 2: Assemble the Vibration Chamber

Use the scissors to snip off the neck of the balloon, cutting about halfway between the opening and the widest part of the balloon.
Stretch the balloon over one of the open ends of the drain pipe. This is your balloon membrane.
Break off a small piece of mirror, approximately 1 x 1 cm2 (it’s okay if the piece is irregularly shaped). If the mirror has a protective film on it, peel it off.
Place a small piece of double-sided tape on the balloon membrane somewhere between the membrane’s center and its outer edge.
Affix the piece of mirror—shiny side up—to the membrane by sticking it onto the exposed side of the double-sided tape.

Step 3: Assemble Frame

Using a hacksaw or PVC cutter, cut the 6-foot (2-meter) length of 1/2-inch diameter, Schedule 40 PVC pipe into the following lengths:
- Two pieces, each 3 cm long
- One piece, 5 cm long
- Three pieces, each 12 cm long
- Two pieces, each 50 cm long
Arrange your 1/2-inch pipe, elbows, and T joints accordingly.
Insert the pieces together, making sure your connections are snug. Note that the frame will form a trapezoid. The narrowing of the pipes helps to better support the vibration chamber.

Step 4: Final Assembly

Place the vibration chamber atop the two 12-cm-long pieces of PVC pipe with the membrane and mirror facing towards the trapezoid. The membrane can touch the T-joints but shouldn’t sit on top of them. The open end of the vibration chamber should extend a little beyond the ends of the PVC frame.
Secure the vibration chamber to the frame by looping two rubber bands around both the two 12 cm-long pipes and the chamber.
Insert the laser pointer into the 12-cm length of half-inch pipe located inside of the trapezoidal area. If the diameter of the laser pointer and the pipe match up, inserting the laser into the tube fully will turn it on. . If the pipe’s diameter is larger than the laser pointer, bulk up the diameter of the laser by wrapping some tape around it until you get a good fit
While your device is on a table, carefully aim the laser beam at the mirror on the membrane. You may need to adjust either the laser pointer or the vibration chamber to get it just right. Use the T-joint to tilt the laser pointer up or down. You might also need to rotate the vibration chamber to line up the laser and the mirror perfectly. Once the laser is hitting the center of the plastic mirror, check to make sure that a crisply reflected laser spot is visible. *Important safety note: Never point a laser into anyone's eyes, including your own! *
Repeat steps 1 to 4 to create another Vocal Visualizer to be able to have two people interacting.

Step 5: Use

With two people, aim each Vocal Visualizers at a wall or against the other person's plain shirt. Again, never aim the laser pointer or the reflected beam directly at your own or anyone else’s face or eyes.
Hold the Vocal Visualizer’s vibration chamber close to the mouth. Hum, sing, speak, or make weird noises into it. As each vocalizes, try changing pitch (frequency) and volume (amplitude) and take note of the different results. If both people are holding the Visualizers against the wall, notice the similarities and differences between the visualization.