Characterization of external ear impulse responses using Golay codes

J Acoust Soc Am. 1992 Aug;92(2 Pt 1):1169-71. doi: 10.1121/1.404045.


This report explains the use of a complementary series, Golay codes, for probing the impulse response of the external ear. The codes are used to measure both the resonance of the human ear canal, using a sealed sound-delivery system, and to measure the transfer function of the pinna, using a free-field source. With two series of 512 binary numbers, the improvement in signal-to-noise ratio over a single impulse approaches the theoretical value of 30.1 dB [10 log(2.512)]. This technique has many of the same properties as maximal-length sequences [M. R. Schroeder, J. Acoust. Soc. Am. 66, 497-500 (1979)], but it has the added advantage that the sequence length is an integer power of two and is, therefore, particularly convenient to use with modern Fourier transform techniques.

Publication types

  • Research Support, U.S. Gov't, Non-P.H.S.
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Ear Canal / physiology*
  • Ear, External / physiology*
  • Hearing / physiology*
  • Humans
  • Loudness Perception / physiology*
  • Pitch Discrimination / physiology*
  • Psychoacoustics
  • Sound Spectrography