Early Reflections

The ``early reflections'' portion of the impulse response is defined as everything up to the point at which a statistical description of the late reverb takes hold.

• Often taken to be the first 100ms
• Better to test for Gaussianness
  • Histogram test for sample amplitudes in 10ms windows
  • Exponential fit ($t_{60}$ match) to EDC (Prony's method, matrix pencil method)
  • Crest factor test (peak/rms)
• Typically implemented using tapped delay lines (TDL)
  (suggested by Schroeder in 1970 and implemented by Moorer in 1979)
• Early reflections should be spatialized (Kendall)
• Early reflections influence spatial impression