Binaural decoder

This tool decodes an Ambisonic sound scene up to a maximal degree $L \leq 5$, for binaural rendering over headphones. Head rotations can be compensated using the rotator upstream. The Head-Related Impulses Responses (HRIR)s are those of a Neumann KU-100 dummy head, provided in¹ at $48$ kHz sampling rate.

Technically, the ambisonic scene is decoded as plane waves in the directions of a spherical Lebedev grid with 50 nodes². For each direction, the resulting signal is then convolved with the corresponding pair of HRIRs. Finally, the binaural signals are summed for each ear. To optimize the computations, decoding and convolution are performed in a single step.

Warning: the HRIRs are $128$-tap filters. For each ambisonic signal, 2 linear convolutions are implemented. As a consequence, at higher degrees, the tool can be very CPU intensive.

Compilation parameter

• L: maximal Spherical Harmonics degree (i.e., Ambisonics order), $0 \leq L \leq 5$.

Inputs / Outputs

• Inputs: $(L+1)^2$
• Outputs: $2$ (left channel, right channel)

User Interface

Element	OSC	Min value	Max value
Inputs level (dB)	levelin	-10	10
Outputs level (dB)	levelout	-10	10