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Line Horneland - The sound in-between



In January 2016 the interactive vocal installation ”The sound in-between” by Line Horneland can be experienced in Sola ruinkirke, a mediaevel church outside Stavanger. The project combines vocal soundscapes and spatiality.

Sound is central to human life, and the aspect of sound is implicit in spatiality. The project thematizes space and sound in an art context, as a place for the listener’s prereflective experiences.

The installation is part of a an ongoing master project at Stord/Haugesund University College, withy me serving as external supervisor.

The installation can be experienced in week 2, 2016:

  • Thursday 14 January 17-19 pm
  • Friday 15 January 17-19 pm
  • Saturday 16 January 12-14 pm
  • Sunday 17 January 12-14 pm

Thanks to Sola kulturhus


Denoising of ambisonic field recordings



I’ve been experimenting lately with what might be the best way to do noise reduction (denoising) of ambisonic field recordings. In some of the recordings from very quiet locations preramp noise is noticeable. I’m not interested in reducing any of the background noise that is part of the recorded ambience itself, I just want to reduce the amount of hiss introduced in the process of recording.

The recordings are done using a SoundField SPS200 mic and a SoundDevice 788T recorder. The resulting recordings are A-format, and I use the SoundField SPS200 plugin to convert the A-format recordings to B-format. Denoising is done using iZotope RX. RX4 is not able to deal with multichannel files, so I have to split the 4-channel recording into two stereo tracks, do noise cancellation on them, and then merge back into four channels again. However there are at least three different approaches to this:

  1. Treat the original A-format recordings, and afterwards convert the processed files to B-format using the SPS200 plug.
  2. Treat the converted B-format recordings.
  3. Decode the B-format files to A-format using the BtoA decoder from Ambisonic Toolkit for Reaper, remove noise, merge, and then re-encode to B-format using the ATK AtoB encoder.

I have done recordings of the SoundDevice at various input levels with no mic connected. The resulting hiss is very similar to the noise that I want to remove, and I use these recordings to train the Denoiser. The resulting curves are stored as a set of presets.

After having experimented over several days, and a lot of useful input from the sursound list, it seems to me that processing of the B-format signals alter some of the spatial information. The resulting spatial image appears to me to be more unstable, and less spatially articulated. If the Denoiser algorithm do alter phase I suspect that it might also impact the original A-format recordings negatively. So I am ending up with the last option above.

One benefit of this is that I can do it all in Reaper, and I don’t have to manually split and merge sound files. It is still a laborious process: At my 4 year old laptop rendering is happening at 1.1 x realtime speed, so there is a lot of waiting.

This blog post was done while waiting for a rendering that took close to 50 minutes to complete. Duh!

Ambisonic Toolkit in the wild



One of the nice things about developing open-source software is seeing where it ends up being used. When ambisonics gets used in advertisements for wild gorilla preservation lodges in Uganda, it’s clearly becoming accessible beyond the electro-acoustic music camp.

The Amsterdam-based music and audio production company has made SpookSync3D, a utiity for syncing view direction and play information between the 360 video player Kolor Eyes and Reaper ambisonic projects using Ambisonic Toolkit for Reaper. The above video gives a clear and thorough presentation of the workflow when designing ambisonic sound for 360 virtual reality using Reraper and Ambisonic Toolkit. has collaborated on several projects with VR Gorilla, another Amsterdam based studio specialising in virtual reality production. One of the projects they have worked on, the Virtual Gorilla app for Android, is available in the Google Play Store.

Happy New Year - Happy New Studio



One of the things I love about the Christmas holiday is that I am often able to set a few days aside for larger tasks that I don’t manage to find the time for during the rest of the year. This often serves as long-term investments, efforts that do not address an imminent deadline, and that do not necessarily pay of immediately. It might be reading up on topics, developing or learning new software, or something else.

This year I have been revamping my studio. The sound absorbers that have been laying around for years are finally up on the walls, and I have set up a 12 speaker 3D ambisonics rig. I still have some calibration to do before I am all set to go, but this definitively feels good.

ATK for Reaper presentation at Ircam


Two weeks ago I did a presentation of Ambisonic Toolkit (ATK) for REAPER at the IRCAM forum. The video is now online. It gives an introduction to first-order ambisonics and the creative workflow that these plugins invite.


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