64 speakers to re-create the cocktail party effect

July 12, 2017 | Case Story

Not everybody is so lucky as to have perfect hearing and to compensate for this new hearing aids are constantly being developed. This is no easy task as human hearing is extremely complex. Although scientists have gained a great deal of knowledge about auditory perception, there are still some unsolved psychoacoustic problems. Specifically in the field of hearing aids, a few important phenomena of human hearing remain a mystery.

Supertool AVIL

To explore these unexplained phenomena of human hearing, the Technical University of Denmark (DTU) has built the Audio Visual Immersion Lab (AVIL) in Copenhagen. One part of AVIL is a 72-channel 3D Audio Higher Order Ambisonics (HOA) system located inside an anechoic chamber; designed and installed by sonible. KEF coaxial speakers ensure perfect point sound sources and three sonible d:24 amplifiers create noise-free amplification on a very narrow 9RU.

DTU AVIL 3D Audio Ambisonic System by sonible Rig 2

This HOA system is the largest of its kind in Europe and can reproduce any acoustic environment imaginable. Such a unique research instrument opens up entirely new possibilities within the field of hearing research. Download the case study for a detailed description and further technical specification of the AVIL project:

Case Study AVIL

AVIL focuses on hearing aid research. Digitization and miniaturization have led to great progress in this field over the past decade, but there still remain unanswered questions. Such as, why do people using hearing aids still experience difficulties in directional listening?

DTU AVIL 3D Audio Ambisonic System by sonible Installation 1

„The Cocktail Party Effect“ – A Challenge

The cocktail party effect has much to do with having the right mixing ratio, and not so much to do with alcohol. It describes the phenomenon that allows us to distinguish a specific sound source amongst many others. We can chat with one person at a cocktail party without becoming distracted by other conversations – hence the term. The cocktail party effect however does not work as well for those who are wearing hearing aids. Hearing aid users often suffer from auditory disorientation that causes frequent, even daily, stressful situations, and, in the worst case, leads to social isolation.

Watch how the system is installed.

All the directional acoustic information that occurs at a real world cocktail party can be accurately reproduced using the Audio Visual Immersion Lab’s Ambisonics 3D audio system. This is an important, though not always fulfilled, requirement for a successful scientific examination of human sensory phenomena.

With the Ambisonics system, researchers now have full control over every singular acoustic parameter, can produce very specific stimuli and thereby measure the resulting psychoacoustic effects on different subjects. With AVIL’s Higher Order Ambisonic 3D audio system all the requirements have been filled to help finally figure out what the cocktail party effect is all about.