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Research CV



Current objectives

Visual evaluation of HRTFs

Computational assessment of HRTFs

Perceptual evaluation of HRTFs

Induction of spatial hearing
to audiovisual speech

Cortical processing of 3-D sound

Spatial hearing and 3-D audio

My scientific research at the Helsinki University of Technology has concentrated on human spatial hearing. Nevertheless, the subject matter is highly multidisciplinary. During the ten pst years I have been working on fields of audio and acoustic engineering, mechnical engineering, electronics, computer science, mathematics, psycho-acoustics, psychology, neuropsychology and statistics, just to name a few on the top of the list.

The fundamentals of my work relate to (measured) head-related transfer functions (HRTFs) that are idiosyncratic responses from a point in the free-field into the ears of the listener (divided by the response of system). HRTFs incorporate all tge basic auditory localization cues received by the auditory system, e.g., binaural interaural time and level differences (ITDs and ILDs), as well as the monaural spectral filtering caused by the human body - especially the torso, pinnae and head.

The measured / modeled head-related transfer functions (or better yet, impulse responses, i.e., HRIRs) can be applied to produce three-dimensional sound, corresponding to our natural spatial hearing percepts. Moreover, the HRTFs reveal the complex phenomena that the sound waves undergo when arriving to the ear canal as well as the high inter-individual variability in the spatial hearing cues and in the perception thereof.

I have studied extensively human spatial hearing applying HRTFs - I have measured more than 200 heads with the high-quality fully automated HRTF measurement / multi-modal experimentation system that I devised. Furthermore, I did extensive perceptual / behavioral experiments with more than 70 subjects. The resuls are published in my numerous publications and in a book form with completely new analyses in my PhD Thesis HRTF repeatability: Analysis of Head-Related Transfer Function Measurements, 383 pages (monograph).

In this Section you will see categorized my current research interests as well as my former research topics, the latter of which are shortly summarized as stated in the abstract of my Doctoriate Thesis.