Navinko iPhone app is an audio augmented reality, social network and navigation tool for Cyclists

October 1st, 2010

This looks very interesting…  I wonder if they target cyclists because it’s easier to get a reliable heading vector – and thus enable full position and orientation-aware binaural audio?  Unfortunately I don’t have an iPhone to try it out on…

Navinko is a social networking service for urban cyclists and pedestrians currently being developed as an iPhone application that uses a unique audio interface.

Through Navinko, the experience of urban discovery is enhanced by giving clues about the location and proximity of friends and groups of cyclists, as well information about points of interest (POI).
Through hands-free voice control, a user can also record and share information relating to their urban dicoveries.
Through the use of a non-intrusive audio interface, users can both interact with the city and other users in an intuitive and safe manner.

Find out more here:


Binaural activity map of Second Order Ambisonics with shelf filtering

September 10th, 2010

Here’s the binaural activity map that results from sampling a second order Ambisonic encode-decode process using a Dirac impulse signal at 36 discrete azimuths (10 degree steps) around the horizontal circle.

The Ambisonic encode-decode used 128 point FIR shelf filters (with 2nd order and 1st order pivot frequencies at 1200Hz and 700Hz respectively), rendered out via 6 virtual speakers to binaural outputs.   (I designed and implemented the rendering system in Matlab and Pd).

The activity map shows the likely lateralization based on Gaik’s algorithm, in which the raw HRTFs are used as a reference for natural ITD and ILD combinations.


Auditory Modelling Toolbox (AMT) 0.2 released

July 29th, 2010

The article below is copied directly from the Spatial Audio Research blog of the Quality and Usability Lab at TU Berlin in order to help spread the word on this toolbox.  The toolbox comes from the AABBA Project (aural assessment by means of binaural algorithms) [pdf], which was introduced by Jens Blauert at the 2009 International Symposium on Auditory and Audiological Research (ISAAR).
I’ve been using their Auditory Modelling Toolbox for the Lindemann analysis below, and found it to be very well developed.

July 26, 2010 in MATLAB by Hagen WierstorfNo comments

A new version of the growing Auditory Modelling Toolbox has been released. The main new feature is a binaural model after Lindemann (1986a) that uses a running cross-correlation with inhibition to predict the perceived lateralization of an auditory event. The output of the model depends on the auditory filters and on the time (see figure below).

To install it, you can download it from Sourceforge. You also have to install the Linear Time/frequency Toolbox. Then in Matlab or Octave just go to the directories of the toolboxes and run:

>> ltfatstart
>> amtstart

After this you are able to use the Lindemann model, see help lindemann for an introduction. To produce the figure below, you can run:

>> demo_lindemann;

Another very nice feature is the function exp_lindemann1986a that is able to reproduce the figures of the Lindemann paper. For example to reproduce figure 6 of the paper, just type exp_lindemann('fig6'). The model is under further development and will include in the next release a version of the method proposed byGaik (1993) to identify natural combinations of ITDs and ILDs. Further a version of theBreebaart model will also be included in one of the next releases.

Binaural activation map

Ambisonics Symposium 2009, IEM, Graz

June 26th, 2009

Today is the second day of the Ambisonics Symposium at IEM, Graz, Austria.
My poster and demonstration is on today, titled:
AmbiGrainer – A Higher Order Ambisonic Granulator in Pd

The paper is available in the online proceedings.

Below is a screenshot of the interface to the patch.  The patch set itself is presently available as a beta by request.

AmbiGrainer is a high quality granulation engine, with sub-block grain timings, capable of producing some very smooth sounds. Grains may be individually panned in 3rd order Ambisonics (with per-grain order specification). Grains may also be specified directly by an external algorithm, or at a meta-level using the provided GUI. A nice feature is the creation of an Ambisonic grain cloud of grains at randomised directions.  The system can run many thousands of grains per second, with 80 simultaneous voices running easily on a 2007 MacBook Pro.

AmbiGrainer interface

SoundDelta- untitled. At Maison des Metallos, Paris.

May 14th, 2009

The audio augmented reality installation: “SoundDelta- untitled” (pdf) will be presented at Maison des Metallos in Paris, from 15th May to 7th June 2009.

SoundDelta- untitled

Dans une zone ponctuée de traces lumineuses au sol, le visiteur muni d’un casque audio est invité à explorer librement l’espace. Au cours de la trajectoire, des sources sonores ponctuelles s’activent lorsqu’on les traverse. La musique est écrite, c’est à dire structurée dans le temps, mais seule la déambulation du spectateur l’actualise, la révèle. Libre à chacun d’inventer son parcours : se laisser porter par la musique, se rapprocher des sources guidé par l’appel de la lumiére, en expérimenter les limites spatiales ou temporelles…

English translation by myself:

In an area punctuated by zones of light on the ground, the visitor, equipped with headphones, is invited to freely explore the space. Sound sources are activated as the listener crosses the zones of light. The music is “written” – that is to say structured in time – but it is only actualised and revealed by the movement of the spectator. The listener is free to make their own way through the piece – to be carried by the music, or guided by the light zones towards individual sounds – to experiment with its spatial and temporal limits.