AES Journal Forum

Wavelet-Based Spatial Audio Format

Document Thumbnail

Ambisonics is a spatial audio technique covering all steps of the audio production chain, from encoding and recording to transmission and decoding, whose building blocks are the spherical harmonics. Some of the drawbacks of low order Ambisonics, like large source spread and small sweet-spot, are directly related to the fact that spherical harmonics do not have compact support on the sphere. In this paper we propose a novel spatial audio format similar in spirit to Ambisonics but which replaces the spherical harmonics by an alternative set of functions with compact support, the spherical wavelets.We develop a complete audio chain from encoding to decoding, using discrete spherical wavelets built on a multiresolution mesh, illustrating with an example implementation of the format. We present a decoding algorithm optimizing acoustic and psychoacoustic parameters that can generate decoding matrices to irregular layouts for both Ambisonics and the new wavelet format. This audio workflow is directly compared with Ambisonics. For an industry-standard loudspeaker layout, we show how we can reach well localized sound sources with almost no negative gains (which are a common issue in most Ambisonics decoder designs). The approach is very flexible: there are different possible incarnations of the wavelet-based audio format, depending on the specific multiresolution mesh and the wavelet family, making possible to customize the format, for example adapting it tomeshes that closely resemble the distribution of loudspeakers in standard layouts.

JAES Volume 68 Issue 9 pp. 613-627; September 2020
Publication Date:

Click to purchase paper as a non-member or you can login as an AES member to see more options.

No AES members have commented on this paper yet.

Subscribe to this discussion

RSS Feed To be notified of new comments on this paper you can subscribe to this RSS feed. Forum users should login to see additional options.

Start a discussion!

If you would like to start a discussion about this paper and are an AES member then you can login here:

If you are not yet an AES member and have something important to say about this paper then we urge you to join the AES today and make your voice heard. You can join online today by clicking here.

AES - Audio Engineering Society