title: Characterization of external ear impulse responses using Golay codes.
abstract: 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.
authors.affiliation: Psychology Department, University of Florida, Gainesville 32611.
authors.forename: B
authors.initials: B
authors.lastname: Zhou
authors.forename: D M
authors.initials: DM
authors.lastname: Green
authors.forename: J C
authors.initials: JC
authors.lastname: Middlebrooks
mesh_terms: D004424:Ear Canal / Q000502:physiology*; D004431:Ear, External / Q000502:physiology*; D006309:Hearing / Q000502:physiology*; D006801:Humans; D008144:Loudness Perception / Q000502:physiology*; D010897:Pitch Discrimination / Q000502:physiology*; D011571:Psychoacoustics; D013018:Sound Spectrography