******** Romeo_HRTF database ********

This text describes the HRTF database acquired within the Romeo project.
For more informations on the Romeo project, see http://www.projetromeo.com/index_en.html

This database contains two parts:
1) measurements on a dummy which we call Theo
2) measurements on the head of the first prototype of Romeo, a humanoid robot.

- The sampling frequency is 16 kHz or 48 kHz

- The number of sensors is 16

******** HRTF file ********

save('Theo_HRTF_16k.mat', ...
'first_freq', ...
'last_freq', ...
'nbfreq', ...
'hrtf', ...
'sphere_x', ...
'sphere_y', ...
'sphere_z', ...
'azimuth', ...
'elevation');

Given N_a the number of azimuths and N_e the number of elevation, the HRTF are
stored in the following order:
azimuth(1), elevation(1)
azimuth(2), elevation(1)
...
azimuth(N_a), elevation(1)
azimuth(1), elevation(2)
azimuth(2), elevation(2)
...
azimuth(N_a), elevation(2)
azimuth(1), elevation(3)
...
...
azimuth(N_a), elevation(N_e)

- 'first_freq' and 'last_freq' are respectevely the first and the last frequency of the hrtf
- 'nbfreq' is the total number of frequency
- 'hrtf' is the hrtf matrix of dimension (number_of_sensors x number_of_spatial_points x nbfreq)
where 'number_of_sensors' is the number of microphones used for the hrtf acquisition (16 microphones)
and 'number_of_spatial_points' is the total number of emission points (azimuth and elevation angles)
- ('sphere_x',sphere_y,sphere_z) are the coordinates of the emission points.
- 'azimuth' is the 72 azimuth angles from 0° to 355 with a step of 5°
- 'elevation' is the elevation angles: -40°, -20°, 0°, 20°, 45°, 60° and 90°

******** HRIR files ********
The HRTFs are organized in a ".mat" files as follow:

- the file name is "Theo_el_az.mat where:

- is one of the 7 elevation angles: -40, -20, 000, 020, 045, 060, 090
- is one of the 72 azimuth angles: 000 to 355 with a step of 5 degrees
--> The evelation and azimuth angles are stored in the file "elevation_azimuth.mat"

- each file contains a matrix "impulse" (of size "length_impulse x 16") of the 16 HRTFs emitted from one elevation and one azimuth