Audiological Acoustics - Hearing with Cochlear Implants studies basic auditory perception of cochlear implant users, people who were previously profoundly deaf. In the case of bilateral implantation left-right localisation of sound sources in the horizontal plane can be achieved, improving speech perception in noise. An open issue concerns the front-back and up-down localisation. In normal hearing pinna cues and head related transfer functions are available for three-dimensional hearing. Utilizing acoustic measurements and numerical simulations, the research aims at transmitting localisation information to the implant electrodes to enable the implant listener to localise sound sources in the sagittal planes. The fast and reliable auditory front-back orientation is seen especially important for implanted children navigating in dangerous environments like heavy traffic roads. Projects