Zeitraum Diagram allows to explore the compositional decisions that led to Zeitraum and also to expand on the idea of the piece through a number of explorative functions implemented in the diagram. Use the H key to toggle the help screen listing all options, which are be briefly explained in the following.
Event frequency: plus (+) and minus (-) keys
With the two keys the event frequency can be changed in 25% steps (+ for faster and - for slower). If the display options (key D) is on the frequency is displayed in Hz (events per second) .
Store/recall constellation: number keys 1 to 9
Constellations of sources, listener and reference position can be stored by hitting one of the keys 1 to 9 while holding down the alternate key. A stored constellation may be recalled by hitting the corresponding key. This allows for an easy comparison of constellations. Only the positions are recorded, no other parameters are stored.
Align: key A
Hitting the A key moves the reference position for the time alignment to the current listening position. If the time alignment is displayed (to be switched on or off with L key), the reference position is displayed as a filled red circle and the aligned (i.e. virtual) speakers are displayed as open red circles.
Display symmetry axes: key B
With the B key the display of the symmetry axes between each pair of sources can be switched on or off. Each point on the axis represented as green line has the same distance to the two corresponding sources.
Centre diagram: key C
The C key can be used to centre the diagram about the listening position. This is useful for keeping the whole diagram displayed inside the window. The scaling can be changed with the up and down keys while holding shift.
Display parameters: key D
With the D key the numerical display of some parameters at the lower end of the window can be switched on and off. Displayed are the speed of sound (in m/s) which can be changed with the left and right cursor keys while holding down the shift key. The default value is the nominal speed of sound in the air of 343 m/s.
Display control options: key H
The display of all options can be switched on or off with the H key.
Display alignment: Key L
The L key toggles the display of the aligned virtual sources as open red circles, the alignment delays as red lines and the reference position as filled red circle. The red lines drawn from the corresponding source represent the additional delay added to the propagation delay to realise the alignment, making sure that it takes the same time for each source signal to arrive at the reference position. The reference position can also be changed dynamically by clicking and dragging it with the mouse.
Display distance circles: key O
With the O key the representation of the distances from the source to listener position as red circles centred on the listener and passing through the real or virtual source can be switched on or off.
Play sonification: key P
Hitting the P key will switch on or off the sonification. To adjust the sound level use the volume of your computer. Make sure that your sound output is not muted.
Reset constellation: key R
With the R key the current constellation of sources can be erased, i.e. all sources are removed and only the listening and the reference position (if switched on with the L key) remain. All other parameters remain unchanged.
Source sequence: key S
The S key alternates the sequence type between a random sequence with repetition control and a fixed sequence based on the source number, which are assigned consecutively when creating sources with shift clicks or the M key.
Source type: key X
Hitting the X key alternates between two source signal types, the exponentially decaying (T60 = 300 ms) pink noise burst used in the installation and an exponentially decaying sine wave. The frequency intervals of the sine waves are tuned to semitones for subsequent sources. The first source is tuned to 440 Hz. The different pitches allow for an easier identification of patterns in the source sequence depending on the S key. For the signals to be heard, the sonification has to be activated with the P key.