Localization results for WFS and NFC-HOA
========================================

A full description of the experiment is provided in H. Wierstorf, Perceptual
Assessment of Sound Field Synthesis, PhD dissertation, TU Berlin, 2014, in
section 4.2 and section 5.1.

Average results
---------------

The files ``average_*`` store the localization results averaged over the
listeners that participated in the single experiments. The results are split
after the applied sound field synthesis method (``wfs``, ``nfchoa``), the
virtual source type (``ps``, ``pw``, ``fs``), and the employed loudspeaker array
(``linear``, ``circular``).

The results are encoded as follows in the csv files:

``condition``: name of used BRS file [1]
``X``: x-position of listener
``Y``: y-position of listener
``phi``: direction of auditory event [2]
``phi_error``: (direction virtual sound event) - (direction auditory event)
``phi_ci``: 95%-confidence interval of phi
``std``: standard deviation of the five repetitions used to measure phi
``std_ci``: 95%-confidence interval of std
``phi_offset``: offset applied to the virtual sound event [3]

[1] The BRS files are available at http://dx.doi.org/10.5281/zenodo.55427
[2] If two values are provided in the form of {2,25}, two auditory events were
perceived at those two positions.
[3] This offset was introduced to have a jitter for the virtual sound event
positions, enabling more randomness to the possible source positions. The
results of ``phi`` and ``phi_error`` are already offset corrected.

Single results
--------------

The folder ``localization_*`` hold the results of the single participants of the
listening experiments.

The results are encoded as follows in the csv files:

``trial_number``: position in the experiment of the presented condition
``mode``: 0 => real single loudspeaker (for calibration); otherwise number of used
loudspeakers (1456 denotes NFC-HOA with 14 loudspeakers, but an order of 28)
``source``: internal number of presented condition
``n``: number of head-tracker (always 1)
``x``: x position of listener (as reported by head-tracker)
``y``: y-position of listener
``z``: z-position of listener
``phi``: horizontal direction of auditory event (includes offset [3])
``real_phi``: direction of virtual sound event (includes offset [3])
``delta``: median direction of auditory event [4]
``stdev``: standard deviation of the listener head orientation during acquisition
of head-tracking data (nine samples after the person presses enter)
``elapsed_time``: time the person needed to localize the source and press enter

[3] The offset was varied for the single conditions. Have a look at the average
result files for the actual offset values.
[4] The participants were advised to only look into the horizontal plane.