Convention Paper
Quantization of 2D Higher Order Ambisonics
AES Convention 124 · Paper 7370 · May 2008
Abstract
The spatial distribution of the quantization noise for a 2-D Higher Order Ambisonics (HOA) signal is inves-
tigated analytically. Uniformly distributed loudspeakers radiating plane waves in a non reverberant environ-
ment and frequency domain quantization are presumed. It is found that employing the same quantization
interval for all orders leads to uniformly distributed quantization noise in space. Assigning a larger quanti-
zation interval (i.e. fewer bits) to higher orders leads to a radially increasing quantization noise. Matching
the quantization error to the reproduction error at the near perfect reconstruction boundary suggests that
as little as four bits per sample can be used for quantization. Furthermore, high-pass ¯ltering the HOA
components opens up for employing as little as three bits per sample. This quantization strategy seems very
promising for reducing the rate of HOA.
