The Effect of Interaural Fluctuation Rate on Correlation Change Discrimination

Research Article


While bilateral cochlear implants (CIs) provide some binaural benefits, these benefits are limited compared to those observed in normal-hearing (NH) listeners. The large frequency-to-electrode allocation bandwidths (BWs) in CIs compared to auditory filter BWs in NH listeners increases the interaural fluctuation rate available for binaural unmasking, which may limit binaural benefits. The purpose of this work was to investigate the effect of interaural fluctuation rate on correlation change discrimination and binaural masking-level differences in NH listeners presented a CI simulation using a pulsed-sine vocoder. In experiment 1, correlation-change just-noticeable differences (JNDs) and tone-in-noise thresholds were measured for narrowband noises with different BWs and center frequencies (CFs). The results suggest that the BW, CF, and/or interaural fluctuation rate are important factors for correlation change discrimination. In experiment 2, the interaural fluctuation rate was systematically varied and dissociated from changes in BW and CF by using a pulsed-sine vocoder. Results indicated that the interaural fluctuation rate did not affect correlation change JNDs for correlated reference noises; however, slow interaural fluctuations increased correlation change JNDs for uncorrelated reference noises. In experiment 3, the BW, CF, and vocoder pulse rate were varied while interaural fluctuation rate was held constant. JNDs increased for increasing BW and decreased for increasing CF. In summary, relatively fast interaural fluctuation rates are not detrimental for detecting changes in interaural correlation. Thus, limiting factors to binaural benefits in CI listeners could be a result of other temporal and/or spectral deficiencies from electrical stimulation.


cochlear implants interaural fluctuation rate correlation change discrimination 


  1. Akeroyd MA, Bernstein LR (2001) The variation across time of sensitivity to interaural disparities: behavioral measurements and quantitative analyses. J Acoust Soc Am 110:2516–2526PubMedCrossRefGoogle Scholar
  2. Akeroyd MA, Summerfield AQ (1999) A binaural analog of gap detection. J Acoust Soc Am 105:2807–2820PubMedCrossRefGoogle Scholar
  3. Bernstein LR, Trahiotis C (1996) The normalized correlation: accounting for binaural detection across center frequency. J Acoust Soc Am 100:3774–3784PubMedCrossRefGoogle Scholar
  4. Bernstein LR, Trahiotis C (1997) The effects of randomizing values of interaural disparities on binaural detection and on discrimination of interaural correlation. J Acoust Soc Am 102:1113–1120PubMedCrossRefGoogle Scholar
  5. Bernstein LR, Trahiotis C (2009) How sensitivity to ongoing interaural temporal disparities is affected by manipulations of temporal features of the envelopes of high-frequency stimuli. J Acoust Soc Am 125:3234–3242PubMedCrossRefGoogle Scholar
  6. Bernstein LR, Trahiotis C, Hyde EL (1998) Inter-individual differences in binaural detection of low-frequency or high-frequency tonal signals masked by narrow-band or broadband noise. J Acoust Soc Am 103:2069–2078PubMedCrossRefGoogle Scholar
  7. Bernstein LR, Trahiotis C, Akeroyd MA, Hartung K (2001) Sensitivity to brief changes of interaural time and interaural intensity. J Acoust Soc Am 109:1604–1615PubMedCrossRefGoogle Scholar
  8. Blauert J (1972) On the lag of lateralization caused by interaural time and intensity differences. Audiology 11:265–270PubMedCrossRefGoogle Scholar
  9. Boehnke SE, Hall SE, Marquardt T (2002) Detection of static and dynamic changes in interaural correlation. J Acoust Soc Am 112:1617–1626PubMedCrossRefGoogle Scholar
  10. Bourbon WT, Jeffress LA (1965) Effect of bandwidth of masking noise on detection of homophasic and antiphasic tonal signals (A). J Acoust Soc Am 39:1180–1181CrossRefGoogle Scholar
  11. Bronkhorst AW, Plomp R (1988) The effect of head-induced interaural time and level differences on speech intelligibility in noise. J Acoust Soc Am 83:1508–1516PubMedCrossRefGoogle Scholar
  12. Buss E, Hall JW 3rd (2010) The role of off-frequency masking in binaural hearing. J Acoust Soc Am 127:3666–3677PubMedCrossRefGoogle Scholar
  13. Buss E, Hall JW 3rd, Grose JH (2003) The masking level difference for signals placed in masker envelope minima and maxima. J Acoust Soc Am 114:1557–1564PubMedCrossRefGoogle Scholar
  14. Buss E, Hall JW 3rd, Grose JH (2007) Individual differences in the masking level difference with a narrowband masker at 500 or 2000 Hz. J Acoust Soc Am 121:411–419PubMedCentralPubMedCrossRefGoogle Scholar
  15. Culling JF (2011) Subcomponent cues in binaural unmasking. J Acoust Soc Am 129:3846–3855PubMedCrossRefGoogle Scholar
  16. Culling JF, Summerfield AQ (1998) Measurements of the binaural temporal window using a detection task. J Acoust Soc Am 103:3540–3553CrossRefGoogle Scholar
  17. Culling JF, Colburn HS, Spurchise M (2001) Interaural correlation sensitivity. J Acoust Soc Am 110:1020–1029PubMedCrossRefGoogle Scholar
  18. Culling JF, Hawley ML, Litovsky RY (2004) The role of head-induced interaural time and level differences in the speech reception threshold for multiple interfering sound sources. J Acoust Soc Am 116:1057–1065PubMedCrossRefGoogle Scholar
  19. Culling JF, Jelfs S, Talbert A, Grange JA, Backhouse SS (2012) The benefit of bilateral versus unilateral cochlear implantation to speech intelligibility in noise. Ear Hear 33:673–682PubMedCrossRefGoogle Scholar
  20. Gabriel KJ, Colburn HS (1981) Interaural correlation discrimination: I. Bandwidth and level dependence. J Acoust Soc Am 69:1394–1401PubMedCrossRefGoogle Scholar
  21. Goupell MJ (2010) Interaural fluctuations and the detection of interaural incoherence. IV. The effect of compression on stimulus statistics. J Acoust Soc Am: 3691–3702Google Scholar
  22. Goupell MJ (2012) The role of envelope statistics in detecting changes in interaural correlation. J Acoust Soc Am 132:1561–1572PubMedCrossRefGoogle Scholar
  23. Goupell MJ, Hartmann WM (2006) Interaural fluctuations and the detection of interaural incoherence: bandwidth effects. J Acoust Soc Am 119:3971–3986PubMedCrossRefGoogle Scholar
  24. Goupell MJ, Hartmann WM (2007) Interaural fluctuations and the detection of interaural incoherence: II. Brief duration noises. J Acoust Soc Am 121:2127–2136PubMedCrossRefGoogle Scholar
  25. Goupell MJ, Kan A, Litovsky RY (2013a) Typical mapping procedures can produce non-centered auditory images in bilateral cochlear-implant users. J Acoust Soc Am 133:EL101–EL107PubMedGoogle Scholar
  26. Goupell MJ, Stoelb C, Kan A, Litovsky RY (2013b) Effect of mismatched place-of-stimulation on the salience of binaural cues in conditions that simulate bilateral cochlear-implant listening. J Acoust Soc Am 133:2272–2287PubMedCrossRefGoogle Scholar
  27. Grantham DW (1982) Detectability of time-varying interaural correlation in narrow-band noise stimuli. J Acoust Soc Am 72:1178–1184PubMedCrossRefGoogle Scholar
  28. Grantham DW (1984) Discrimination of dynamic interaural intensity differences. J Acoust Soc Am 76:71–76PubMedCrossRefGoogle Scholar
  29. Grantham DW, Wightman FL (1978) Detectability of varying interaural temporal differences. J Acoust Soc Am 63:511–523PubMedCrossRefGoogle Scholar
  30. Hafter ER, Carrier SC (1970) Masking-level differences obtained with a pulsed tonal masker. J Acoust Soc Am 47:1041–1047PubMedCrossRefGoogle Scholar
  31. Hall JW, Tyler RS, Fernandes MA (1983) Monaural and binaural auditory frequency resolution measured using bandlimited noise and notched-noise masking. J Acoust Soc Am 73:894–898PubMedCrossRefGoogle Scholar
  32. Henning GB, Yasin I, Witton C (2007) Remote masking and the binaural masking-level difference. In: Kollmeier B, Klump G, Hohmann V, Langemann U, Mauermann M, Uppenkamp S, and Verhey JL (ed) Hearing - From Sensory Processing to Perception. Springer Verlag, Berlin, pp. 457–466Google Scholar
  33. Jain M, Gallagher DT, Koehnke J, Colburn HS (1991) Fringed correlation discrimination and binaural detection. J Acoust Soc Am 90:1918–1926PubMedCrossRefGoogle Scholar
  34. Jeffress LA, Blodgett HC, Sandel TT, Wood CL 3rd (1956) Masking of tonal signals. J Acoust Soc Am 28Google Scholar
  35. Kan A, Stoelb C, Litovsky RY, Goupell MJ (2013) Effect of mismatched place-of-stimulation on binaural fusion and lateralization in bilateral cochlear-implant users. J Acoust Soc Am 134:2923–2936PubMedCrossRefGoogle Scholar
  36. Ketten DR, Skinner MW, Wang G, Vannier MW, Gates GA, Neely JG (1998) In vivo measures of cochlear length and insertion depth of Nucleus cochlear implant electrode arrays. Ann Otol Rhinol Laryngol Suppl 175:1–16PubMedGoogle Scholar
  37. Koehnke J, Colburn HS, Durlach NI (1986) Performance in several binaural-interaction experiments. J Acoust Soc Am 79:1558–1562PubMedCrossRefGoogle Scholar
  38. Lavandier M, Culling JF (2010) Prediction of binaural speech intelligibility against noise in rooms. J Acoust Soc Am 127:387–399PubMedCrossRefGoogle Scholar
  39. Litovsky RY, Jones GL, Agrawal S, van Hoesel R (2010) Effect of age at onset of deafness on binaural sensitivity in electric hearing in humans. J Acoust Soc Am 127:400–414PubMedCrossRefGoogle Scholar
  40. Litovsky RY, Goupell MJ, Godar S, Grieco-Calub T, Jones GL, Garadat SN, Agrawal S, Kan A, Todd A, Hess C, Misurelli S (2012) Studies on bilateral cochlear implants at the University of Wisconsin's Binaural Hearing and Speech Laboratory. J Am Acad Audiol 23:476–494PubMedCentralPubMedGoogle Scholar
  41. Loizou PC (2006) Speech processing in vocoder-centric cochlear implants. In: Moller A (ed) Cochlear and brainstem implants. Karger, Basel, pp 109–143Google Scholar
  42. Loizou PC, Hu Y, Litovsky R, Yu G, Peters R, Lake J, Roland P (2009) Speech recognition by bilateral cochlear implant users in a cocktail-party setting. J Acoust Soc Am 125:372–383PubMedCrossRefGoogle Scholar
  43. Long CJ, Carlyon RP, Litovsky RY, Downs DH (2006) Binaural unmasking with bilateral cochlear implants. J Assoc Res Otolaryngol 7:352–360PubMedCentralPubMedCrossRefGoogle Scholar
  44. Lu T, Litovsky R, Zeng FG (2010) Binaural masking level differences in actual and simulated bilateral cochlear implant listeners. J Acoust Soc Am 127:1479–1490PubMedCrossRefGoogle Scholar
  45. Lu T, Litovsky R, Zeng FG (2011) Binaural unmasking with multiple adjacent masking electrodes in bilateral cochlear implant users. J Acoust Soc Am 129:3934–3945PubMedCrossRefGoogle Scholar
  46. Macpherson EA, Middlebrooks JC (2002) Listener weighting of cues for lateral angle: the duplex theory of sound localization revisited. J Acoust Soc Am 111:2219–2236PubMedCrossRefGoogle Scholar
  47. Majdak P, Laback B (2009) Effects of center frequency and rate on the sensitivity to interaural delay in high-frequency click trains. J Acoust Soc Am 125:3903–3913PubMedCentralPubMedCrossRefGoogle Scholar
  48. McFadden D, Russell WE, Pulliam KA (1972) Monaural and binaural masking patterns for a low-frequency tone. J Acoust Soc Am 51:534–543CrossRefGoogle Scholar
  49. Moore BC, Glasberg BR (1983) Suggested formulae for calculating auditory-filter bandwidths and excitation patterns. J Acoust Soc Am 74:750–753PubMedCrossRefGoogle Scholar
  50. Nelson DA, Donaldson GS, Kreft H (2008) Forward-masked spatial tuning curves in cochlear implant users. J Acoust Soc Am 123:1522–1543PubMedCentralPubMedCrossRefGoogle Scholar
  51. Nitschmann M, Verhey JL (2012) Modulation cues influence binaural masking-level difference in masking-pattern experiments. J Acoust Soc Am 131:EL223–EL228PubMedGoogle Scholar
  52. Nitschmann M, Verhey JL, Kollmeier B (2009) The role of across-frequency processes in dichotic listening conditions. J Acoust Soc Am 126:3188–3198PubMedCrossRefGoogle Scholar
  53. Poon BB, Eddington DK, Noel V, Colburn HS (2009) Sensitivity to interaural time difference with bilateral cochlear implants: development over time and effect of interaural electrode spacing. J Acoust Soc Am 126:806–815PubMedCrossRefGoogle Scholar
  54. Rice SO (1954) Mathematical analysis of random noise. In: Wax N (ed) Selected papers on noise and stochastic processes. Dover, New York, pp 133–294Google Scholar
  55. Sever JC Jr, Small AM Jr (1979) Binaural critical masking bands. J Acoust Soc Am 66:1343–1350PubMedCrossRefGoogle Scholar
  56. Shannon RV, Zeng FG, Kamath V, Wygonski J, Ekelid M (1995) Speech recognition with primarily temporal cues. Science 270:303–304PubMedCrossRefGoogle Scholar
  57. van de Par S, Kohlrausch A (1997) A new approach to comparing binaural masking level differences at low and high frequencies. J Acoust Soc Am 101:1671–1680PubMedCrossRefGoogle Scholar
  58. van de Par S, Kohlrausch A (1999) Dependence of binaural masking level differences on center frequency, masker bandwidth, and interaural parameters. J Acoust Soc Am 106:1940–1947PubMedCrossRefGoogle Scholar
  59. van de Par S, Luebken B, Verhey JL, Kohlrausch A (2012) Off-frequency BMLD: The role of monaural processing. In: Moore BCJ, Patterson RD, Winter IM, Carlyon RP, Gockel HE (ed) Basic Aspects of Hearing: Physiology and Perception. Springer, Cambridge, England, pp. 293–301Google Scholar
  60. van der Heijden M, Joris PX (2009) Interaural correlation fails to account for detection in a classic binaural task: Dynamic ITDs dominate NOSπ detection. J Assoc Res Otolaryngol 11:113–131PubMedCentralPubMedCrossRefGoogle Scholar
  61. Van Deun L, van Wieringen A, Francart T, Scherf F, Dhooge IJ, Deggouj N, Desloovere C, Van de Heyning PH, Offeciers FE, De Raeve L, Wouters J (2009) Bilateral cochlear implants in children: binaural unmasking. Audiol Neuro Otol 14:240–247CrossRefGoogle Scholar
  62. Van Deun L, van Wieringen A, Francart T, Buchner A, Lenarz T, Wouters J (2011) Binaural unmasking of multi-channel stimuli in bilateral cochlear implant users. J Assoc Res Otolaryngol 12:659–670PubMedCentralPubMedCrossRefGoogle Scholar
  63. van Hoesel RJM (2004) Exploring the benefits of bilateral cochlear implants. Audiol Neuro Otol 9:234–246CrossRefGoogle Scholar
  64. van Hoesel RJM (2007) Sensitivity to binaural timing in bilateral cochlear implant users. J Acoust Soc Am 121:2192–2206PubMedCrossRefGoogle Scholar
  65. van Hoesel RJM, Bohm M, Pesch J, Vandali A, Battmer RD, Lenarz T (2008) Binaural speech unmasking and localization in noise with bilateral cochlear implants using envelope and fine-timing based strategies. J Acoust Soc Am 123:2249–2263PubMedCrossRefGoogle Scholar
  66. Webster FA (1951) The influence of interaural phase on masked thresholds: I. The role of interaural time-deviation. J Acoust Soc Am 23:452–462CrossRefGoogle Scholar
  67. Wightman FL (1971) Detection of binaural tones as a function of masker bandwidth. J Acoust Soc Am 50:623–636PubMedCrossRefGoogle Scholar
  68. Wightman FL, Kistler DJ (1992) The dominant role of low-frequency interaural time differences in sound localization. J Acoust Soc Am 91:1648–1661PubMedCrossRefGoogle Scholar
  69. Yasin I, Henning GB (2012) The effects of noise-bandwidth, noise-fringe duration, and temporal signal location on the binaural masking-level difference. J Acoust Soc Am 132:327–338PubMedCrossRefGoogle Scholar
  70. Zurek PM (1991) Probability distributions of interaural phase and level differences in binaural detection stimuli. J Acoust Soc Am 90:1927–1932PubMedCrossRefGoogle Scholar
  71. Zurek PM, Durlach NI (1987) Masker-bandwidth dependence in homophasic and antiphasic tone detection. J Acoust Soc Am 81:459–464PubMedCrossRefGoogle Scholar
  72. Zwicker E, Henning GB (1984) Binaural masking-level differences with tones masked by noises of various bandwidths and levels. Hear Res 14:179–183PubMedCrossRefGoogle Scholar

Copyright information

© Association for Research in Otolaryngology 2013

Authors and Affiliations

  1. 1.Department of Hearing and Speech SciencesUniversity of MarylandCollege ParkUSA
  2. 2.Waisman CenterUniversity of WisconsinMadisonUSA

Personalised recommendations