PhET Faraday's Law - Sonification Sketches

Balancing Layers of Sonification

Given that both the light bulb and volt meter are sonified, how would the audio mix be designed so that a user relying on audio can:

1. distinguish between the two sources?
2. cognitively focus on the source they want?

What about field lines?

Not clear at this moment whether sonification is required for the field lines. The field lines reveal two concepts:

1. Field lines have a direction - the direction of the field changes the polarity of the voltage.
2. Quantity of field lines covering the coil affects quantity of flux.

It may be better to describe this? Maybe there's a way to sonify it?

Sketch 3 - Positive/Negative tempo mapping

• Tempo increases relative to the voltage being measured.
  
  • Faster the tempo, higher the voltage being observed.
  • Slower the tempo, lower the voltage.
  • Example: Sketch 3 Example - Low to High Voltage.mp3 - Transition from low to high occurs at 4 second mark.
• Represent positive and negative with two different but related sounds.
  • Example: Negative to Positive Voltage (MP3 Audio, 10 seconds) - Transition from negative to positive occurs at 4 second mark.
• Note: the examples use a simple clicking sound for illustration purposes.
• When voltage reaches maximum on either end, sound plays at a constant, quick tempo.
• Light bulb is represented by a humming sound that increases in volume with brightness
  • Example: Sketch 3 Example - Dim to Bright Bulb.mp3 - Transition from dim to bright occurs at 4 second mark.

Light bulb humming sound - Recorded by Mike Koenig - http://soundbible.com/1085-Halogen-Light.html

Sonifying the Light Bulb

Although the light bulb may appear to be providing the same information as the volt meter (just no difference whether it is negative or positively charged), the light bulb is important to secondary learning outcomes such as understanding the nature of an alternating current (i.e. the currently can flow either way and still power the bulb). Thus it's important to sonify the light bulb differently than the volt meter.

• The light bulb could be represented by a buzzing sound that is played when it is lit. The buzzing intensifies with the brightness.

Volt Meter Sketch 2 - Positive/Negative Pitch Mapping

• Buzzing electricity sounds that increase or decrease pitch depending on positive and negative measurement.
  • a higher pitch for positive voltage readings that increases in pitch as the needle reaches the max positive
  • a lower pitch for negative voltage readings that decreases in pitch as the needle reaches the max negative
  • Perception problem:
    • Pitch mapping may be incorrectly be associated with quantity.
    • i.e. Higher pitch may incorrectly be associated with more voltage, and lower pitch may be incorrectly associated with less voltage.

Volt Meter Sketch 1 - Positive/Negative Stereo Panning

• Possible sounds:

  • Clicking dial sounds that increases in frequency the faster it moves. Example (on Youtube).

  • Buzzing electricity sounds that increase intensity (pitch or volume?) Example (on Youtube).

• Volt meter left-right pan for negative-positive

  • Perception Problem:

    • Stereo panning can be confusing as the direction of the meter may not match the direction of the magnet movement.

    • i.e. The sound be perceived to be moving left, but the magnet is moving right.

Possible Events to Sonify

• Increase brightness
• Decrease brightness
• Increase / decrease negative volt meter (see Volt Meter Sketches 1 through 3 below)
• Increase / decrease positive volt meter (see Volt Meter Sketches 1 through 3 below)
• Meter reaches 0
• Meter reaches max. negative
• Meter reaches max. positive