Measuring long impulse responses with pseudorandom sequences and sweep signals

Antoni Torras Rosell (Invited author), Finn Jacobsen (Invited author)

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In architectural acoustics, background noise, loudspeaker nonlinearities, and time variances are the most common disturbances that can compromise a measurement. The effects of such disturbances on measurement of long impulse responses with pseudorandom sequences (maximum-length sequences (MLS) and inverse repeated sequences (IRS)) and with linear and logarithmic sweep signals have been examined. The results reveal that the sweep method can provide a significant reduction of the effect of distortion compared with MLS/IRS techniques but, unlike what is claimed in the literature, sweep signals cannot reject all distortion artifacts from the causal part of the estimated impulse response. In all cases, an improvement of 3 dB in signal-to-noise ratio can be achieved if the measurement time is doubled either by averaging over two excitations or by doubling the length of the excitation signal. The time-frequency selectivity performed by the sweep technique is found to yield higher immunity to impulsive noise and time variances.
Original languageEnglish
Title of host publicationProceedings of Inter-Noise 2010
Publication date2010
Publication statusPublished - 2010
Event39th International Congress and Exposition on Noise Control Engineering - Lisbon, Portugal
Duration: 15 Jun 201016 Jun 2010
Conference number: 39


Conference39th International Congress and Exposition on Noise Control Engineering
Internet address


  • Time-variance
  • Pseudorandom noise
  • Distortion
  • Sweep
  • Noise

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