Sound conductor 2.0

I elaborated on the human sound conductor experiment from last term (please see this post, and this one). I have set up a distributed sound system that only functions when two people are willing to come into close proximity: they have to touch.

Salsa parties are often organized at bars of clubs where people meet and dance, outside a teaching environment (most venues also offer classes before the social dancing, but more advanced dancers often don’t attend these and come later). My classmate Maria made a very funny comment when she compared a dance class to speed dating: in your average dance class the ladies will change partners every few minutes so you can practice with everyone, it is considered good to get used to several different partners to become a versatile dancer that can follow/lead anyone. So it happens that you might awkwardly introduce yourselves quickly – class just goes on – and practice a step for a few minutes before the lady is sent off to the next partner. But overall, you will be caught in very intimate movements together, even more so when you start doing drops, dips and other showy stuff.

In salsa, which I happen to know better than other couple dancing styles, you don’t always touch each other, you can break away for shines where you dance in front of each other doing some individual moves. The real leading-following however, occurs by means touching of course. In this system the dancers will not really have a choice: they can dance to the upbeat song, but not together, or they can choose to dance together but then will the sexuality of the dancing is heavily emphasized.

Strategies

I’ve had some trouble coming up with a way to cut the ground wire in the human sound conductor (see the other post on the human sound conductor). I will try a few new strategies to try and overcome this problem. In this new experiment the sound is probably not what is being conducted, but the conductive quality of the skin is nevertheless used to break or complete an electronic circuit upon touching/releasing. To ground the circuit I will try these things:

  • Dancing on a wet rug
  • Dancing on a metal plate or creating some sort of floor grid
  • Dancing in a fountain (or less glamorous: a kiddies’ pool
  • Conductive body paint
  • Conductive thread weaved through gloves

If any of these work I will have to create something that can send an ON of OFF signal to a microcontroller/computer that changes the music and turns off the light. This could be:

  • An IR (infrared) transmitter and receiver set
  • A radio signal
  • etcetera

Wet carpet to ground the circuit

I tried this strategy on the carpet in the lab and using the wet carpet conducted a signal (with ground wire intact) as well as ground perfectly. Even when I placed the ground wire of the sound source (iPod) and that of the sound output (amp and speaker) more than a meter away from each other, it still gave a clear sound. Before flooding the entire lab, I will try it at home on a bigger surface to see what it does.

Set up for the wet carpet conducting the ground (human conducting the sound signal as usual)

Set up for the wet carpet conducting the ground (human conducting the sound signal as usual)

One meter of wet carpet

One meter of wet carpet

So this is very good. But I have to keep the ground apart from the signal, they can’t both go through the same human body, so I will make shoe tassels from the conductive thread I have, and these tassels will have a wire running up to the ipod and amp/speaker that will be attached to the dancer’s bodies by e.g. a belt. I made a rough sketch of what this would look like. If the tassels don’t conduct well enough I could see if I can get some tap dancing shoes with the metal soles, or build some other conductive cover to hug the soles of the feet to make a connection.

Sketch for human sound conductor on wet carpet, incl shoe tassels

Sketch for human sound conductor on wet carpet, incl shoe tassels

Tap shoes for sound conductor on wet rug

Tap shoes for sound conductor on wet rug

Below some videos of the wet rug experiment:

  • Conducting the sound signal through the rug – ground wire intact, no human sound conduction
  • Conducting the sound signal indirectly: through the rug and through human body – ground wire intact
  • Conducting the ground through the rug – sound via human conductor
  • Conducting the ground through the rug, but iPod ground and speaker ground approx. 1 meter apart – sound via human conductor.
Carpet conducting sound signal (link to youtube)

Carpet conducting sound signal (link to youtube)

Conducting sound through carpet indirectly (link to youtube)

Conducting sound through carpet indirectly (link to youtube)

Conducting ground through carpet (link to youtube)

Conducting ground through carpet (link to youtube)

Ground through carpet, sound through human (link to youtube)

Ground through carpet, sound through human 1 meter apart (link to youtube)

I tested this idea of a wet rug as ground conductor on a larger scale in my home, with 10 kilos/litres of water and an old rug. It proves to be really conductive, so that’s perfect. The cold, wet rug even feels pleasant to dance on, which is a bonus. I’ve made two conductive gloves, with isolated wires attached leading to either amplifier/speaker or ipod so it can be carried on the body without getting the signals confused: when the ground and sound signal are both conducted through the body you short-circuit the system and you won’t get a sound. With these gloves I can keep the signal isolated from the ground that is going through my body (via a piece of stripped ground wire attached to my upper arm with a sweat band, through my body and then via my bare feet through the wet rug). You can see this in the video below. Although I unfortunately did not have a partner when I conducted and filmed this experiment, the speaker that was now sitting on the floor, connected to the rug, can in fact be carried by another barefoot dancer in similar fashion.

One glove connected to an iPod (yellow wire is ground that is connected to skin)

One glove connected to an iPod (yellow wire is ground that is connected to skin)

One glove connected to the amplifier and speaker (yellow wire is ground)

One glove connected to the amplifier and speaker (yellow wire is ground)

Experiment with wet rug and conductive gloves (link to youtube)

Experiment with wet rug and conductive gloves (link to youtube)

Human sound conductor with gloves (link to youtube)

Human sound conductor with gloves (link to youtube)


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