Live Experiment on Sonification of Human EEG
Gerold Baier (University of Manchester) and Thomas Hermann (Bielefeld University) performed within the contemporary music festival Wien Modern 2008. as opening event of the Wien Modern 2008 series "MUSIC & THE BRAIN", Nov. 1 - 5, 2008, Vienna
- Live Experiment on Sonification of Human EEG
- Presentation of Selectd Sonification Examples for Brain Activity
| Event Organization & Sonification: | jointly by Thomas Hermann & Gerold Baier |
| EEG Technician: | Alexander Lenhardt |
| Sound Technician (Vienna Concert Hall): | Peter Böhm |
| Test subject for the live experiment: | Alvin Lucier |
| Acknowledgement: | Data were kindly provided by Ulrich Stephani, Hiltrud Muhle, Gerd Wigand, Universitätsklinikum Schleswig-Holstein, Kiel, and Klaus Lehnertz and Christian E. Elger, Clinic for Epileptology, University of Bonn. |
Summary
The authors presented at this opening event of the theme "Music & the Brain" a novel technique to make the activity of the human brain audible and thereby intuitively graspable. Sonification enables a new access to the phenomena of normal and pathologic dynamics of the brain. Input signals are the electric activity of the brain measured with electroencephalography (EEG).
The first part of the evening was a live demonstration of the sonification technique. Brain waves were measured live on stage and transformed into audible sound via the systematic approach of event-based sonification, so that their rhythmic and polyrhythmic structure can be followed. As a prominent subject, the composer Alvin Lucier served to deliver his brain waves as stimulus.
In the second part of the programme, various sonifications of physiological data were presented, including electrocardiogram sonifications but focussing mainly on EEG sonifications of the wake state, sleep stages, photo stimulation, and epilepsy. The audience was able to experience brain activity in a novel way. The event was a premiere, the first multi-channel EEG sonification live and in real-time.
Live Experiment: Sonification of Human EEG
 | The photo shows Thomas Hermann, Alexander Lenhardt, Alvin Lucier and Gerold Baier (left to right) during the live sonification experiment in Vienna on November 1, 2008. The sonification technique is Event-based Sonification, developed by Gerold Baier and Thomas Hermann (see references), which represents multivariate EEG as a stream of audible events. The subject Alvin Lucier whose brain waves have been used as input for the experiment can be seen wearing an EEG cap. The projection shows a visual display of the recorded data. The sound was projected using the spatial sound system of the concert hall. Alpha rhythms, beta activity in the temporal lobe and muscle artefacts due to blinking were sonified. |
Presentation of Selected Sonification Examples for Brain Activity
The second part of the programme "Live Sonification of Human EEG" was a presentation of 12 sonifications. The sonification methods of Event-based Sonification and Vocal EEG Sonification were developed by Thomas Hermann and Gerold Baier (see references) and represent different ways how EEG data can be transformed into meaningful sound. The examples had a duration of approx. 3-5 minutes and were framed by a visual dynamic primer which provided some keywords that faded in and out. Out of the visual silence of a black wall and a dark room, the sonification started so that these sounds could be perceived without any distraction. The spatial character caused the audience to be immersed into the situation, giving the impression that they are put into the center of a human brain.
 | Sonification Example S4 (mp3, stereo downmix, 2.8M): Normal EEG background activity as measured from 27 electrodes in an awake subject with eyes open. No pronounced rhythms, little variation in overall amplitude but various subtle micropatterns. |
 | Sonification Example S5 (mp3, stereo downmix, 2.7M): Fast and loud rhythms of sleep spindles during stage 2 sleep. Spindle rhythms occur in different areas and can vary in their length and mean frequency. |
 | Sonification Example S6 (mp3, stereo downmix, 3.9M): Deep sleep is characterized by slow waves with large amplitudes that are picked up all over the scalp. An overall impression of irregularity prevails. |
 | Sonification Example S7 (mp3, stereo downmix, 0.9M): A recurring rhythmic pattern in the theta range (4-7 beats per second) can be heard in a patient with epilepsy. |
 | Sonification Example S8 (mp3, stereo downmix, 4.2M): Periodic flashes of light lead to enhanced synchronization of brain activity |
 | Sonification Example S9 (mp3, stereo downmix, 3.9M): Normal irregular background EEG of the awake state is interrupted twice by the 3 per second spike and wave pattern of an absence seizure. |
 | Sonification Example S10 (mp3, stereo downmix, 9.2M): From a normal background pattern there is a slowly evolving abnormal rhythm in the theta range that gains strength and spreads to finally involve all measured electrodes in this example of a focal seizure. |
 | Sonification Example S11 (mp3, 3.1M): Vocal sonification of an absence seizure with its pronounced rhythm. The vocal pattern reflects the typical spike-and-wave complex. 1/4 real-time. |
 | Sonification Example S12 (mp3, 1.5M): Vocal sonification of an absence seizure with its pronounced rhythm. The vocal pattern reflects the typical spike-and-wave complex. 1/2 real-time. |
References
- T. Hermann and G. Baier. Die Sonifikation des menschlichen EEG, Katalogbeitrag zu Wien Modern 2008, Berno Odo Polzer (Ed.), , Verein Wien modern, p. 25-27., Wien, 2008.
- G. Baier, T. Hermann, U. Stephani, Event-based sonification of EEG rhythms in real time. Clin. Neurophysiol. 118, 1377 (2007), (website)
- T. Hermann, G. Baier, U. Stephani, H. Ritter, Kernel Regression Mapping for Vocal EEG Sonification. 14th International Conference on Auditory Display, Montreal, Canada, June 24-27 (2008). (website)