Spatial Stream Segregation

  • John C. MiddlebrooksEmail author
Part of the Springer Handbook of Auditory Research book series (SHAR, volume 60)


“Stream segregation” refers to a listener’s ability to disentangle interleaved sequences of sounds, such as the ability to string together syllables from one talker in the presence of competing talkers. Spatial separation of sound sources is a key factor that enables the task of segregation. Psychophysical tasks that require listeners to integrate sounds across locations demonstrate that listeners can overcome spatial separation of sources, suggesting that space is a relatively weak segregating factor. Contrary to that suggestion tasks that require listeners to isolate a sound sequence within a complex background demonstrate robust benefits of spatial separation of the target from other sources. This chapter reviews psychophysical studies that show weak versus strong spatial effects on streaming and shows that the spatial acuity of stream segregation can approach the limits of acuity of spatial hearing. Responses from auditory cortex in anesthetized animals are presented demonstrating that single neurons can exhibit spatial stream segregation by synchronizing selectively to one or the other of two interleaved sound sequences. The results from animals imply that perceptually segregated sound sequences are represented in auditory cortex by discrete mutually synchronized neural populations. Human magneto- and electroencephalographic results then are described showing selective enhancement of cortical responses to attended versus unattended sounds. Available results lead to a picture showing bottom-up segregation of sound sources by brainstem mechanisms on the basis of spatial and other cues, followed by top-down selection of particular neural populations that could underlie perceptual auditory objects of attention.


Auditory cortex Rhythmic masking release Scene analysis Spatial hearing Spatial streaming Stream integration Spatial release from masking 



I thank Georg Klump, Lauren Javier, and Justin Yao for their helpful suggestions on the manuscript. This chapter was completed while the author was a resident fellow at the Hanse-Wissenschaftskolleg in Delmenhorst, Germany. The author’s work is supported by the National Institutes of Health grant R01 DC000420.

Compliance with Ethics Requirements

John Middlebrooks has no conflicts of interest.


  1. Atiani, S., Elhilali, M., David, S. V., Fritz, J. B., & Shamma, S. A. (2009). Task difficulty and performance induce diverse adaptive patterns in gain and shape of primary auditory cortical receptive fields. Neuron, 61, 467–480.CrossRefPubMedGoogle Scholar
  2. Bizley, J. K., Walker, K. M., Silverman, B. W., King, A. J., & Schnupp, J. W. (2009). Interdependent encoding of pitch, timbre, and spatial location in auditory cortex. The Journal of Neuroscience, 29, 2064–2075.CrossRefPubMedPubMedCentralGoogle Scholar
  3. Boehnke, S. E., & Phillips, D. P. (2005). The relation between auditory temporal interval processing and sequential stream segregation examined with stimulus laterality differences. Perception and Psychophysics, 67, 1088–1101.CrossRefPubMedGoogle Scholar
  4. Bregman, A. S. (1990). Auditory scene analysis: The perceptual organization of sound. Cambridge, MA: MIT Press.Google Scholar
  5. Briley, P. M., Kitterick, P. T., & Summerfield, A. Q. (2013). Evidence for opponent process analysis of sound source location in humans. Journal of the Association for Research in Otolaryngology, 14, 973–983.CrossRefGoogle Scholar
  6. Broadbent, D. E., & Ladefoged, P. (1957). On the fusion of sounds reaching different sense organs. The Journal of the Acoustical Society of America, 29, 708–710.CrossRefGoogle Scholar
  7. Brosch, M., & Schreiner, C. E. (1997). Time course of forward masking tuning curves in cat primary auditory cortex. Journal of Neurophysiology, 77, 923–943.PubMedGoogle Scholar
  8. Calford, M. B., & Semple, M. N. (1995). Monaural inhibition in cat auditory cortex. Journal of Neurophysiology, 73, 1876–1891.PubMedGoogle Scholar
  9. Carl, D., & Gutschalk, A. (2012). Role of pattern, regularity, and silent intervals in auditory stream segregation based on inter-aural time differences. Experimental Brain Research, 224, 557–570.CrossRefPubMedGoogle Scholar
  10. Cherry, C. E. (1953). Some experiments on the recognition of speech, with one and two ears. The Journal of the Acoustical Society of America, 25, 975–979.CrossRefGoogle Scholar
  11. Creutzfeldt, O. D., Hellweg, F. C., & Schreiner, C. (1980). Thalamocortical transformations of responses to complex auditory stimuli. Experimental Brain Research, 39, 87–104.CrossRefPubMedGoogle Scholar
  12. Cutting, J. E. (1976). Auditory and linguistic processes in speech perception: Inferences from six fusions in dichotic listening. Psychological Review, 2, 114–140.CrossRefGoogle Scholar
  13. Ding, N., Chatterjee, M., & Simon, J. Z. (2013). Robust cortical entrainment to the speech envelope relies on the spectro-temporal fine structure. NeuroImage, 88, 41–46.CrossRefPubMedPubMedCentralGoogle Scholar
  14. Ding, N., & Simon, J. (2012a). Emergence of neural encoding of auditory objects while listening to competing speakers. Proceedings of the National Academy of Sciences of the USA, 109, 11854–11859.CrossRefPubMedPubMedCentralGoogle Scholar
  15. Ding, N., & Simon, J. (2012b). Neural coding of continuous speech in auditory cortex during monaural and dichotic listening. Journal of Neurophysiology, 107, 78–89.CrossRefPubMedGoogle Scholar
  16. Dingle, R. N., Hall, S. E., & Phillips, D. P. (2010). A midline azimuthal channel in human spatial hearing. Hearing Research, 268, 67–74.CrossRefPubMedGoogle Scholar
  17. Duffour-Nikolov, C., Tardif, E., Maeder, P., Thiran, A. B., et al. (2012). Auditory spatial deficits following hemispheric lesions: Dissociation of explicit and implicit processing. Neuropsychological Rehabilitation, 22, 674–696.CrossRefPubMedGoogle Scholar
  18. Edmonds, B. A., & Culling, J. F. (2005a). The role of head-related time and level cues in the unmasking of speech in noise and competing speech. Acta Acustica united with Acustica, 91, 546–553.Google Scholar
  19. Edmonds, B. A., & Culling, J. F. (2005b). The spatial unmasking of speech: Evidence for within-channel processing of interaural time delay. The Journal of the Acoustical Society of America, 117, 3069–3078.CrossRefPubMedGoogle Scholar
  20. Elhilali, M., Ma, L., Micheyl, C., Oxenham, A., & Shamma, S. (2009). Temporal coherence in the perceptual organization and cortical representation of auditory scenes. Neuron, 61, 317–329.CrossRefPubMedPubMedCentralGoogle Scholar
  21. Fishman, Y., Reser, D., Arezzo, J., & Steinschneider, M. (2001). Neural correlates of auditory stream segregation in primary auditory cortex of the awake monkey. Hearing Research, 151, 167–187.CrossRefPubMedGoogle Scholar
  22. Fritz, J. B., Elhilali, M., & Shamma, S. A. (2007). Adaptive changes in cortical receptive fields induced by attention to complex sounds. Journal of Neurophysiology, 98, 2337–2346.CrossRefPubMedGoogle Scholar
  23. Fritz, J. B., Shamma, S. A., Elhilali, M., & Klein, D. J. (2003). Rapid task-related plasticity of spectrotemporal receptive fields in primary auditory cortex. Nature Neuroscience, 6, 1216–1223.CrossRefPubMedGoogle Scholar
  24. Füllgrabe, C., & Moore, B. C. J. (2012). Objective and subjective measures of pure-tone stream segregation based on interaural time differences. Hearing Research, 291, 24–33.CrossRefPubMedGoogle Scholar
  25. Furukawa, S., Xu, L., & Middlebrooks, J. C. (2000). Coding of sound-source location by ensembles of cortical neurons. The Journal of Neuroscience, 20, 1216–1228.PubMedGoogle Scholar
  26. Griffiths, T. D., & Warren, J. D. (2004). What is an auditory object? Nature Review of Neuroscience, 5, 887–892.CrossRefGoogle Scholar
  27. Harrington, I. A., Stecker, G. C., Macpherson, E. A., & Middlebrooks, J. C. (2008). Spatial sensitivity of neurons in the anterior, posterior, and primary fields of cat auditory cortex. Hearing Research, 240, 22–41.CrossRefPubMedPubMedCentralGoogle Scholar
  28. Hartmann, W. M., & Johnson, D. (1991). Stream segregation and peripheral channeling. Music Perception, 9, 155–184.CrossRefGoogle Scholar
  29. Hartmann, W. M., & Rakerd, B. (1993). Auditory spectral discrimination and the localization of clicks in the sagittal plane. The Journal of the Acoustical Society of America, 94, 2083–2092.CrossRefPubMedGoogle Scholar
  30. Hofman, P. M., & Van Opstal, J. A. (1998). Spectro-temporal factors in two-dimensional human sound localization. The Journal of the Acoustical Society of America, 103, 2634–2648.CrossRefPubMedGoogle Scholar
  31. Hukin, R. W., & Darwin, C. J. (1995). Effects of contralateral presentation and of interaural time differences in segregating a harmonic from a vowel. The Journal of the Acoustical Society of America, 98, 1380–1387.CrossRefGoogle Scholar
  32. Ihlefeld, A., & Shinn-Cunningham, B. (2008a). Spatial release from energetic and informational masking in a selective speech identification task. The Journal of the Acoustical Society of America, 123, 4369–4379.CrossRefPubMedGoogle Scholar
  33. Ihlefeld, A., & Shinn-Cunningham, B. (2008b). Disentangling the effects of spatial cues on selection and formation of auditory objects. The Journal of the Acoustical Society of America, 124, 2224–2235.CrossRefPubMedGoogle Scholar
  34. Kidd, G., Jr., Best, V., & Mason, C. R. (2008). Listening to every other word: Examining the strength of linkage variables in forming streams of speech. The Journal of the Acoustical Society of America, 124, 3793–3802.CrossRefPubMedPubMedCentralGoogle Scholar
  35. King, A. J., & Middlebrooks, J. C. (2011). Cortical representation of auditory space. In J. Winer & C. Schreiner (Eds.), The auditory cortex (pp. 329–341). New York: Springer Science+Business Media.CrossRefGoogle Scholar
  36. Kuhn, G. F. (1977). Model for the interaural time differences in the azimuthal plane. The Journal of the Acoustical Society of America, 62, 157–167.CrossRefGoogle Scholar
  37. Lee, C.-C., & Middlebrooks, J. (2011). Auditory cortex spatial sensitivity sharpens during task performance. Nature Neuroscience, 14, 108–114.CrossRefPubMedGoogle Scholar
  38. Lee, C.-C., & Middlebrooks, J. (2013). Specialization for sound localization in fields A1, DZ, and PAF of cat auditory cortex. Journal of the Association for Research in Otolaryngology, 14, 61–82.CrossRefPubMedGoogle Scholar
  39. Lomber, S., & Malhotra, S. (2008). Double dissociation of ‘what’ and ‘where’ processing in auditory cortex. Nature Neuroscience, 11, 609–616.CrossRefPubMedGoogle Scholar
  40. Macpherson, E. A., & Middlebrooks, J. C. (2000). Localization of brief sounds: Effects of level and background noise. The Journal of the Acoustical Society of America, 108, 1834–1849.CrossRefPubMedGoogle Scholar
  41. Macpherson, E. A., & Middlebrooks, J. C. (2002). Listener weighting of cues for lateral angle: The duplex theory of sound localization revisited. The Journal of the Acoustical Society of America, 111, 2219–2236.CrossRefPubMedGoogle Scholar
  42. Magezi, D. A., & Krumbholz, K. (2010). Evidence of opponent-channel coding of interaural time differences in human auditory cortex. Journal of Neurophysiology, 104, 1997–2007.CrossRefPubMedPubMedCentralGoogle Scholar
  43. May, B. J., & Huang, A. Y. (1996). Sound orientation behavior in cats. I. Localization of broadband noise. The Journal of the Acoustical Society of America, 100, 1059–1069.CrossRefPubMedGoogle Scholar
  44. Mesgarani, N., & Chang, E. F. (2012). Selective cortical representation of attended speaker in multi-talker speech perception. Nature, 485, 233–236.CrossRefPubMedGoogle Scholar
  45. Micheyl, C., & Oxenham, A. J. (2010). Objective and subjective psychophysical measures of auditory stream integration and segregation. Journal of the Association for Research in Otolaryngology, 11, 709–724.CrossRefPubMedPubMedCentralGoogle Scholar
  46. Micheyl, C., Tian, B., Carlyon, R. P., & Rauschecker, J. P. (2005). Perceptual organization of tone sequences in the auditory cortex of awake macaques. Neuron, 48, 139–148.CrossRefPubMedGoogle Scholar
  47. Mickey, B. J., & Middlebrooks, J. C. (2003). Representation of auditory space by cortical neurons in awake cats. The Journal of Neuroscience, 23, 8649–8663.PubMedGoogle Scholar
  48. Middlebrooks, J. C., & Bremen, P. (2013). Spatial stream segregation by auditory cortical neurons. The Journal of Neuroscience, 33, 10986–11001.CrossRefPubMedPubMedCentralGoogle Scholar
  49. Middlebrooks, J. C., Clock, A. E., Xu, L., & Green, D. M. (1994). A panoramic code for sound location by cortical neurons. Science, 264, 842–844.CrossRefPubMedGoogle Scholar
  50. Middlebrooks, J. C., & Green, D. M. (1990). Directional dependence of interaural envelope delays. The Journal of the Acoustical Society of America, 87, 2149–2162.CrossRefPubMedGoogle Scholar
  51. Middlebrooks, J. C., & Green, D. M. (1991). Sound localization by human listeners. Annual Review of Psychology, 42, 135–159.CrossRefPubMedGoogle Scholar
  52. Middlebrooks, J. C., & Onsan, Z. A. (2012). Stream segregation with high spatial acuity. The Journal of the Acoustical Society of America, 132, 3896–3911.CrossRefPubMedPubMedCentralGoogle Scholar
  53. Miller, L. M., & Recanzone, G. H. (2009). Populations of auditory cortical neurons can accurately encode acoustic space across stimulus intensity. Proceedings of the National Academy of Sciences of the USA, 106, 5931–5935.CrossRefPubMedPubMedCentralGoogle Scholar
  54. Moore, B. C. J., & Gockel, H. (2002). Factors influencing sequential stream segregation. Acta Acustica, 88, 320–332.Google Scholar
  55. Moore, B. C. J., & Gockel, H. (2012). Properties of auditory stream formation. Philosophical Transactions of the Royal Society B: Biological Sciences, 367, 919–931.CrossRefGoogle Scholar
  56. Phillips, D. P. (2008). A perceptual architecture for sound lateralization in man. Hearing Research, 238, 124–132.CrossRefPubMedGoogle Scholar
  57. Pressnitzer, D., Sayles, M., Micheyl, C., & Winter, I. (2008). Perceptual organization of sound begins in the auditory periphery. Current Biology, 18, 1124–1128.CrossRefPubMedPubMedCentralGoogle Scholar
  58. Sach, A. J., & Bailey, P. J. (2004). Some characteristics of auditory spatial attention revealed using rhythmic masking release. Perception and Psychophysics, 66, 1379–1387.CrossRefPubMedGoogle Scholar
  59. Salminen, N. H., May, P. J., Alku, P., & Tiitinen, H. (2009). A population rate code of auditory space in the human cortex. PLoS ONE, 26, e7600.CrossRefGoogle Scholar
  60. Saupe, K., Keoelsch, S., & Rubsamen, R. (2010). Spatial selective attention in a complex auditory environment such as polyphonic music. The Journal of the Acoustical Society of America, 127, 472–480.CrossRefPubMedGoogle Scholar
  61. Schadwinkel, S., & Gutschalk, A. (2010). Activity associated with stream segregation in human auditory cortex is similar for spatial and pitch cues. Cerebral Cortex, 20, 2863–2873.CrossRefPubMedGoogle Scholar
  62. Schreiner, C., & Urbas, J. (1988). Representation of amplitude modulation in the auditory cortex of the cat. II. Comparison between cortical fields. Hearing Research, 32, 49–63.CrossRefPubMedGoogle Scholar
  63. Shaw, E. A. G. (1974). Transformation of sound pressure level from the free field to the eardrum in the horizontal plane. The Journal of the Acoustical Society of America, 56, 1848–1861.CrossRefPubMedGoogle Scholar
  64. Snyder, J., & Alain, C. (2007). Toward a neurophysiological theory of auditory stream segregation. Psychological Bulletin, 133, 780–799.CrossRefPubMedGoogle Scholar
  65. Stainsby, T. H., Fullgrabe, C., Flanagan, H. J., Waldman, S. K., & Moore, B. C. J. (2011). Sequential streaming due to manipulation of interaural time differences. The Journal of the Acoustical Society of America, 130, 904–914.CrossRefPubMedGoogle Scholar
  66. Stecker, G. C., Harrington, I. A., & Middlebrooks, J. C. (2005). Location coding by opponent neural populations in the auditory cortex. PLoS Biology, 3, 520–528.CrossRefGoogle Scholar
  67. Stein, B. E., & Meredith, M. A. (1993). The merging of the senses., Cognitive Neuroscience Series Cambridge, MA: MIT Press.Google Scholar
  68. Takanen, M., Raitio, T., Santala, O., Alku, P., & Pulkki, V. (2013). Fusion of spatially separated vowel formant cues. The Journal of the Acoustical Society of America, 134, 4508–4517.CrossRefPubMedGoogle Scholar
  69. Thiran, A. B., & Clarke, S. (2003). Preserved use of spatial cues for sound segregation in a case of spatial deafness. Neuropsychologia, 41, 1254–1261.CrossRefPubMedGoogle Scholar
  70. Tollin, D. J., Populin, L. C., Moore, J. M., Ruhland, J. L., & Yin, T. C. (2005). Sound-localization performance in the cat: The effect of restraining the head. Journal of Neurophysiology, 93, 1223–1234.CrossRefPubMedGoogle Scholar
  71. van Noorden, L. P. A. S. (1975). Temporal coherence in the perception of tone sequences. PhD dissertation, Eindhoven: University of Technology.Google Scholar
  72. Vliegen, J., Moore, B. C., & Oxenham, A. J. (1999). The role of spectral and periodicity cues in auditory stream segregation, measured using a temporal discrimination task. The Journal of the Acoustical Society of America, 106, 938–945.CrossRefPubMedGoogle Scholar
  73. Wightman, F. L., & Kistler, D. J. (1992). The dominant role of low-frequency interaural time differences in sound localization. The Journal of the Acoustical Society of America, 91, 1648–1661.CrossRefPubMedGoogle Scholar
  74. Woods, T. M., Lopez, S. E., Long, J. H., Rahman, J. E., & Recanzone, G. H. (2006). Effects of stimulus azimuth and intensity on the single-neuron activity in the auditory cortex of the alert macaque monkey. Journal of Neurophysiology, 96, 3323–3337.CrossRefPubMedGoogle Scholar
  75. Woods, W. S., & Colburn, H. S. (1992). Test of a model of auditory object formation using intensity and interaural time difference discrimination. The Journal of the Acoustical Society of America, 91, 2894–2902.CrossRefPubMedGoogle Scholar
  76. Yin, P., Fritz, J. B., & Shamma, S. A. (2014). Rapid spectrotemporal plasticity in primary auditory cortex during behavior. The Journal of Neuroscience, 34, 4396–4408.CrossRefPubMedPubMedCentralGoogle Scholar

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Authors and Affiliations

  1. 1.Department of Otolaryngology, Department of Neurobiology & Behavior, Department of Cognitive Sciences, Department of Biomedical Engineering, Center for Hearing ResearchUniversity of CaliforniaIrvineUSA

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