The spatial distribution of the quantization noise for a 2-D Higher Order Ambisonics (HOA) signal is investigated analytically. Uniformly distributed loudspeakers radiating plane waves in a non reverberant environment 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 quantization 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 filtering 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.
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