Parameters file

The settings for a test are stored in a parameters file (which is a simple text file). An example parameters file is shown below:

angles : -70, -60, -50, -40, -30, -20, -10, 0, 10, 20, 30, 40, 50, 60, 70
labels : 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15
channels : 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15
n_chan : 15
n_blocks : 1
stim_list_file : stim_list.csv
randomize : true
demo_stim : pink_noises/noise1.wav
demo_stim_lev : 65

The following fields need to be specified in a parameters file:

  • angles: the azimuth angles (in degrees) at which the sounds are presented. Note that a 0° angle indicates straight ahead, a 90° angle is to the right, and a -90° angle to the left.

  • labels: a label for each of the angles, this can be a number or a letter (e.g., a, b, c, ecc.)

  • channels: the channel of the soundcard that will be used to present a sound at the corresponding angle

  • n_chan: the total number of channels for the setup

  • n_blocks: the number of blocks, that is how many times the test will be repeated

  • stim_list_file: the path (absolute or relative) to the file containing the stimulation list (see below)

  • randomize: if true the stim_list_file will be shuffled before each block repetition

  • demo_stim: the path to the WAV file to be used for the demo

  • demo_stim_lev: the sound level (in dB SPL) to be used for the demo

Stimulation file

Stimulation files specify the stimuli that will be played on each trial of the test. Figure Example stimulation file. shows an example stimulation file.

Example stimulation file

Example stimulation file.

Each row of the file represents a trial. Stimulation files contain the following columns:

  • angle: the angle at which the sound will be presented (stimuli will be sent to the corresponding soundcard channel as specified in the parameters file)

  • sound_file: the path (relative or absolute) to the WAV file to be played

  • condition: an optional label specifying the experimental condition

  • level: the base sound level (in dB SPL) at which the sound will be presented (this assumes that sound_source_id has been correctly calibrated)

  • roving: a level rove, actual sound level will be euqual to the base level plus a value drawn from a random uniform distribution between +/- the roving level

  • feedback: if true, feedback will be given to the listener at the end of each trial