A novel approach to counting waves in a room


  • John O'Keefe O'Keefe Acoustics University of Toronto


This paper was originally about what we generally call a “reflection counter”. After further study using methods of chaos theory, it was found that the procedure is not a reflection counter but might be more aptly described as a wave counter.  For one thing, the so-called “reflection count” was far less than what geometrical acoustical theory would predict, typically in the hundreds rather than the thousands.  In a room, positive and negative interference effects seem to “smooth out” reflections and reduce the number of countable waves.  As they do with any wave phenomena from waves on the water to the sun in the sky.  But according to traditional geometrical theory, reflected sound in a room cannot be so attenuated.  Geometrical theory does not include wave effects.  But of course the reflections do attenuate, through diffusion, dissipation and, more importantly, wave interference effects.  This paper proposes the shift from use of a wave counter to a reflection counter.  In acoustics this is a subtle but profound difference.

Author Biography

John O'Keefe, O'Keefe Acoustics University of Toronto

Sole Prepriator of O'Keefe AcousticsAdjunct Professor Mechanical Engineering



How to Cite

O’Keefe J. A novel approach to counting waves in a room. Canadian Acoustics [Internet]. 2017Aug.30 [cited 2021May17];45(3):74-5. Available from: https://jcaa.caa-aca.ca/index.php/jcaa/article/view/3152



Proceedings of the Acoustics Week in Canada