by edwin.lang -

Impulse #3 – Audio Workshop

I got the chance to take part in a music workshop where we build three types of microphones:

  1. Binaural Microphone
  2. Piezo Microphone
  3. Electromagnetic Field Microphone

If you want to build one of the microphones on your own, you will need the following parts.

Binaural Microphone:

  • 2x electret capsule mod. CME-12 (or similar omnidirectional)
  • 1x mini stereo jack male solderable aerial 3.5 mm
  • 1m coaxial audio stereo cable

Piezo Microphone:

  • piezoelectric ceramic disc buzzer model 27EE41
  • 1 mini mono jack male solderable aerial 3.5 mm
  • 1m coaxial audio stereo cable (separate each channel into two we only need one channel)

Electromagnetic Field Microphone:

  • 1 magnetic inductor (choose the one with the highest power)
  • 1 mini mono jack male solderable aerial 3.5 mm
  • 1m coaxial audio stereo cable (separate each channel into two we only need one channel)

Additional Equipment:

  • soldering iron
  • solder wire
  • electrical tape

While the piezo- and electromagnetic microphones will be connected via mono audio cable and jack, the binaural microphone needs a stereo cable and jack. The following soldering example refers to the piezo microphone but will be for all three microphones the same.

At the beginning you need to remove at the endings of the cable a small part of the outer insulation (see image below). Now you can see a red insulated wire and a loose wire around it. While the loose wire when twisted together acts the negative pole, the red insulated wire acts as the positive pole.

After this step you can start to solder one end of the cable on to the piezo microphone. The red wire should be soldered on to the silver area and the other one on to the golden area. It is important that each cable is only connected to one of the areas and doesn’t overlap with the second one.

Note: For additional protection of the solder points you can put hot glue on the entire surface, as the contact surface for the microphone is the back side.

The final step will be to solder the second end of the audio cable on to the audio jack. The red wire (positive pole) needs to be soldered in the inner part of the jack and the loose wire (negative pole) needs to be soldered on to the outer part (see image below).

Now put the cover back on the audio jack and test your new microphone.

Here you can listen to an example recording I made by scratching on a wooden plank.

by edwin.lang -

Prototyping Overview

Until now the focus of my research was about communicating social and environmental problems with the help of tangible user interfaces. In this blogpost I want to concretize my current topic of my master thesis and focus on one specific environmental problem – “melting ice sheets and their impact on sea level rise – starting a so called “chain reaction”.

So how should such an exhibit be designed, to not only offer great experience but also stating a call to action?

What is the perfect symbiosis between the digital and analog medium for communicating sensitive topics like climate change?

Staying true to the concept of multisensory experiences I would like to create an exhibit that has the following layers of abstraction:

Physical feedback

For the physical representation of an ice cap, I want to build a three-dimensional model out of sticks covered by an elastic mesh. The height of the sticks can be controlled separately with a motor, giving the impression of a shape changing constantly.

c Edwin Lang

Audio feedback

By recording the cracking of an ice bucket with contact microphones, I want to create a sound similar to a cracking ice cap.

https://freesound.org/embed/sound/iframe/268023/simple/large/

Video feedback

In terms of video, I want to project morphing organic shapes onto the physical representation of the ice cap. The shapes could be generated with programs like OpenFrameworks and real data sets of melting caps[1]. With the help of machine learning and algorithms the complexity of the data sets could be drastically reduced – however further research and testing is needed[2].

Credits images: https://pin.it/4OqiwA6


User Interface

The visitors should be able to see changes of the ice cap based on their ecological footprint. The ecological footprint gives an indicator on the greenhouse gas emissions, can be converted to emitted energy and further be linked to the capability of melting ice.

The interface itself has yet to be explored but will be of great importance to successfully link the individual ecological footprint with the ice cap and make the visitors emotionally bonded to the exhibit.

References:

[1] https://umap-learn.readthedocs.io/en/latest/
[2] Algorithmus: https://umap-learn.readthedocs.io/en/latest/