Calum (Cal) Armstrong

PhD Student

ORCID: 0000-0002-6211-6282


  • HRTF measurement protocols
  • Binaural audio
  • Ambisonics


Cal graduated with a Masters degree in Electronic Engineering in 2016 before starting his PhD with the AudioLab shortly after. His undergraduate thesis explored the diversity and reproduction of sound source radiation patterns as he developed ‘the Globe’, a prototype loudspeaker with dynamic directivity for case-specific Room Impulse Response measurement.

His current work focuses on advancing state of the art HRTF measurement techniques to support an optimized binaural renderer for virtual Ambisonic reproduction. As part of this he led the development of the SADIE II HRTF database and has since begun to explore near field measurements utilizing custom loudspeaker arrays. His research is heavily reliant on a foundation of Ambisonic theory as well as the measurement and Digital Signal Processing of binaural Impulse Responses.

Associated Projects

  • Improvements in Binaural Based Ambisonic Decoding
  • SADIE: Spatial Audio for Domestic Interactive Entertainment

Highlighted Publications

“A Perceptual Evaluation of Individual and Non-Individual HRTFs: A Case Study of the SADIE II Database” – Cal Armstrong, Lewis Thresh, Damian T. Murphy and Gavin Kearney

“A Bi-RADIAL Approach to Ambisonics” – Cal Armstrong, Damian T. Murphy, and Gavin Kearney

“A Perceptual Spectral Difference Model for Binaural Signals” – Cal Armstrong, Thomas Mckenzie, Damian T. Murphy and Gavin Kearney