Abstract

Dynamic images of individual signs of American Sign Language (ASL) with a resolution of 96 × 64 pixels were bandpass filtered in adjacent frequency bands. Intelligibility was determined by testing deaf subjects fluent in ASL. The following results were obtained. (1) By iteratively varying the center frequencies and bandwidths of the spatial bandpass filters, it was possible to divide the original signal into four different component bands of high intelligibility. (2) The measured temporal-frequency spectrum was approximately the same in all bands. (3) The masking of signals in band i by noise in band j was found to be inversely proportional to log |fsignal/fnoise|. At constant performance, the ratio of root-mean-square signal amplitude to noise amplitude, s/n, was the same for bands 2, 3, and 4 and higher for band 1. (4) When weak signals i and j were added linearly, there was a slight intelligibility advantage for signals in the same band (i = j) compared with signals in adjacent bands and for signals in adjacent bands compared with signals in distant bands.

© 1988 Optical Society of America

Full Article  |  PDF Article

References

  • View by:
  • |
  • |
  • |

  1. For a succinct review, see N. Graham, “Detection and identification of near-threshold visual patterns,” J. Opt. Soc. Am. A 2, 1468–1482 (1985).
    [Crossref] [PubMed]
  2. For a review, see L. A. Olzak, J. P. Thomas, “Seeing spatial patterns,” in Handbook of Perception and Performance, K. R. Boff, L. Kaufman, J. P. Thomas, eds. (Wiley, New York, 1986), Chap. 7.
  3. G. E. Legge, D. G. Pelli, G. S. Rubin, M. M. Schleske, “Psycho-physics of reading—I. Normal vision,” Vision Res. 25, 239–252 (1985).
    [Crossref]
  4. D. H. Parish, G. Sperling, “Object spatial frequency, not retinal spatial frequency, determines identification efficiency,” Invest. Ophthalmol. Vis. Sci. Suppl. 28, 359 (1987).
  5. G. Sperling, D. H. Parish, “Object spatial frequencies, retinal spatial frequencies, noise, and the efficiency of discrimination,” in Mathematical Studies in Perception and Cognition (Department of Psychology, New York University, New York, N.Y., 1987).
  6. J. D. Schein, M. T. Delk, The Deaf Population of the United States (National Association of the Deaf, Silver Spring Md., 1974).
  7. G. Sperling, “Bandwidth requirements for video transmission of American Sign Language and finger spelling,” Science 210, 797–799 (1980).
    [Crossref] [PubMed]
  8. G. Sperling, “Video transmission of American Sign Language and finger spelling: present and projected bandwidth requirements,” IEEE Trans. Commun. COM-29, 1993–2002 (1981).
    [Crossref]
  9. G. Sperling, M. Landy, Y. Cohen, M. Pavel, “Intelligible encoding of ASL image sequences at extremely low information rates,” Comput. Vision Graph. Image Process. 31, 335–391 (1985).
    [Crossref]
  10. T. R. Riedl, “Spatial frequency selectivity and higher level human information processing,” doctoral dissertation (New York University, New York, N.Y., 1985).
  11. P. J. Burt, E. H. Adelson, “The Laplacian pyramid as a compact image code,” IEEE Trans. Commun. COM-31, 532–540 (1983).
    [Crossref]
  12. G. B. Henning, B. G. Hertz, J. L. Hinton, “Effects of different hypothetical detection mechanisms on the shape of spatial-frequency filters inferred from making experiments. I. Noise masks,” J. Opt. Soc. Am. 71, 574–581 (1981).
    [Crossref] [PubMed]
  13. G. Legge, J. Foley, “Contrast masking in human vision,” J. Opt. Soc. Am. 70, 1458–1471 (1980).
    [Crossref] [PubMed]
  14. S. Stecher, C. Sigel, R. V. Lange, “Composite adaptation and spatial frequency interactions,” Vision Res. 13, 2527–2531 (1973).
    [Crossref] [PubMed]
  15. C. F. Strohmeyer, B. Julesz, “Spatial-frequency masking in vision: critical bands and spread of masking,” J. Opt. Soc. Am. 62, 1221–1232 (1972).
    [Crossref]
  16. C. F. Strohmeyer, S. Klein, B. M. Dawson, L. Spillmann, “Low spatial-frequency channels in human vision: adaption and masking,” Vision Res. 22, 225–233 (1982).
    [Crossref]
  17. D. J. Tolhurst, “Adaptation to square-wave gratings: inhibition between spatial frequency channels in the human visual system,” J. Physiol. 226, 231–248 (1972).
    [PubMed]
  18. H. R. Wilson, J. R. Bergen, “A four mechanism model for threshold spatial vision,” Vision Res. 19, 19–32 (1979).
    [Crossref] [PubMed]
  19. J. P. Chandler, “stepit,” in Quantum Chemistry Program Exchange (Department of Chemistry, Indiana University, Bloomington, Ind., 1965).
  20. J. Nachmias, A. Wever, “Discrimination of simple and complex gratings,” Vision Res. 15, 217–223 (1975).
    [Crossref] [PubMed]
  21. D. J. Tolhurst, L. P. Barfield, “Interactions between spatial frequency channels,” Vision Res. 18, 951–958 (1978).
    [Crossref] [PubMed]
  22. N. Graham, J. Nachmias, “Detection of grating patterns containing two spatial frequencies: a comparison of single-channel and multiple models,” Vision Res. 11, 251–259 (1971).
    [Crossref] [PubMed]
  23. N. Graham, “Psychophysics of spatial-frequency channels,” in Perceptual Organization, M. Kubovy, J. Pomerantz, eds. (Erlbaum Halstead, Potomac, Md., 1980), pp. 1–25.
  24. M. Pavel, G. Sperling, T. Riedl, A. Vanderbeek, “Limits of visual communication: the effects of signal-to-noise ratio on the intelligibility of American Sign Language,” J. Opt. Soc. Am. A 4, 2355–2365 (1987).
    [Crossref] [PubMed]
  25. C. R. Carlson, R. W. Klopfenstein, “Spatial-frequency model for hyperacuity,” J. Opt. Soc. Am. A 2, 1747–1751 (1985).
    [Crossref]
  26. J. Nachmias, R. V. Sansbury, “Grating contrast: discrimination maybe better than detection,” Vision Res. 14, 1039–1042 (1974).
    [Crossref] [PubMed]
  27. C. F. Strohmeyer, S. Klein, “Evidence against narrow-band spatial frequency channels in human vision: the detectability of frequency modulated gratings,” Vision Res. 15, 899–910 (1975).
    [Crossref]
  28. D. G. Pelli, “Effects of visual noise,” doctoral dissertation (University of Cambridge, Cambridge, 1981).

1987 (2)

D. H. Parish, G. Sperling, “Object spatial frequency, not retinal spatial frequency, determines identification efficiency,” Invest. Ophthalmol. Vis. Sci. Suppl. 28, 359 (1987).

M. Pavel, G. Sperling, T. Riedl, A. Vanderbeek, “Limits of visual communication: the effects of signal-to-noise ratio on the intelligibility of American Sign Language,” J. Opt. Soc. Am. A 4, 2355–2365 (1987).
[Crossref] [PubMed]

1985 (4)

C. R. Carlson, R. W. Klopfenstein, “Spatial-frequency model for hyperacuity,” J. Opt. Soc. Am. A 2, 1747–1751 (1985).
[Crossref]

For a succinct review, see N. Graham, “Detection and identification of near-threshold visual patterns,” J. Opt. Soc. Am. A 2, 1468–1482 (1985).
[Crossref] [PubMed]

G. E. Legge, D. G. Pelli, G. S. Rubin, M. M. Schleske, “Psycho-physics of reading—I. Normal vision,” Vision Res. 25, 239–252 (1985).
[Crossref]

G. Sperling, M. Landy, Y. Cohen, M. Pavel, “Intelligible encoding of ASL image sequences at extremely low information rates,” Comput. Vision Graph. Image Process. 31, 335–391 (1985).
[Crossref]

1983 (1)

P. J. Burt, E. H. Adelson, “The Laplacian pyramid as a compact image code,” IEEE Trans. Commun. COM-31, 532–540 (1983).
[Crossref]

1982 (1)

C. F. Strohmeyer, S. Klein, B. M. Dawson, L. Spillmann, “Low spatial-frequency channels in human vision: adaption and masking,” Vision Res. 22, 225–233 (1982).
[Crossref]

1981 (2)

G. B. Henning, B. G. Hertz, J. L. Hinton, “Effects of different hypothetical detection mechanisms on the shape of spatial-frequency filters inferred from making experiments. I. Noise masks,” J. Opt. Soc. Am. 71, 574–581 (1981).
[Crossref] [PubMed]

G. Sperling, “Video transmission of American Sign Language and finger spelling: present and projected bandwidth requirements,” IEEE Trans. Commun. COM-29, 1993–2002 (1981).
[Crossref]

1980 (2)

G. Legge, J. Foley, “Contrast masking in human vision,” J. Opt. Soc. Am. 70, 1458–1471 (1980).
[Crossref] [PubMed]

G. Sperling, “Bandwidth requirements for video transmission of American Sign Language and finger spelling,” Science 210, 797–799 (1980).
[Crossref] [PubMed]

1979 (1)

H. R. Wilson, J. R. Bergen, “A four mechanism model for threshold spatial vision,” Vision Res. 19, 19–32 (1979).
[Crossref] [PubMed]

1978 (1)

D. J. Tolhurst, L. P. Barfield, “Interactions between spatial frequency channels,” Vision Res. 18, 951–958 (1978).
[Crossref] [PubMed]

1975 (2)

J. Nachmias, A. Wever, “Discrimination of simple and complex gratings,” Vision Res. 15, 217–223 (1975).
[Crossref] [PubMed]

C. F. Strohmeyer, S. Klein, “Evidence against narrow-band spatial frequency channels in human vision: the detectability of frequency modulated gratings,” Vision Res. 15, 899–910 (1975).
[Crossref]

1974 (1)

J. Nachmias, R. V. Sansbury, “Grating contrast: discrimination maybe better than detection,” Vision Res. 14, 1039–1042 (1974).
[Crossref] [PubMed]

1973 (1)

S. Stecher, C. Sigel, R. V. Lange, “Composite adaptation and spatial frequency interactions,” Vision Res. 13, 2527–2531 (1973).
[Crossref] [PubMed]

1972 (2)

C. F. Strohmeyer, B. Julesz, “Spatial-frequency masking in vision: critical bands and spread of masking,” J. Opt. Soc. Am. 62, 1221–1232 (1972).
[Crossref]

D. J. Tolhurst, “Adaptation to square-wave gratings: inhibition between spatial frequency channels in the human visual system,” J. Physiol. 226, 231–248 (1972).
[PubMed]

1971 (1)

N. Graham, J. Nachmias, “Detection of grating patterns containing two spatial frequencies: a comparison of single-channel and multiple models,” Vision Res. 11, 251–259 (1971).
[Crossref] [PubMed]

Adelson, E. H.

P. J. Burt, E. H. Adelson, “The Laplacian pyramid as a compact image code,” IEEE Trans. Commun. COM-31, 532–540 (1983).
[Crossref]

Barfield, L. P.

D. J. Tolhurst, L. P. Barfield, “Interactions between spatial frequency channels,” Vision Res. 18, 951–958 (1978).
[Crossref] [PubMed]

Bergen, J. R.

H. R. Wilson, J. R. Bergen, “A four mechanism model for threshold spatial vision,” Vision Res. 19, 19–32 (1979).
[Crossref] [PubMed]

Burt, P. J.

P. J. Burt, E. H. Adelson, “The Laplacian pyramid as a compact image code,” IEEE Trans. Commun. COM-31, 532–540 (1983).
[Crossref]

Carlson, C. R.

Chandler, J. P.

J. P. Chandler, “stepit,” in Quantum Chemistry Program Exchange (Department of Chemistry, Indiana University, Bloomington, Ind., 1965).

Cohen, Y.

G. Sperling, M. Landy, Y. Cohen, M. Pavel, “Intelligible encoding of ASL image sequences at extremely low information rates,” Comput. Vision Graph. Image Process. 31, 335–391 (1985).
[Crossref]

Dawson, B. M.

C. F. Strohmeyer, S. Klein, B. M. Dawson, L. Spillmann, “Low spatial-frequency channels in human vision: adaption and masking,” Vision Res. 22, 225–233 (1982).
[Crossref]

Delk, M. T.

J. D. Schein, M. T. Delk, The Deaf Population of the United States (National Association of the Deaf, Silver Spring Md., 1974).

Foley, J.

Graham, N.

For a succinct review, see N. Graham, “Detection and identification of near-threshold visual patterns,” J. Opt. Soc. Am. A 2, 1468–1482 (1985).
[Crossref] [PubMed]

N. Graham, J. Nachmias, “Detection of grating patterns containing two spatial frequencies: a comparison of single-channel and multiple models,” Vision Res. 11, 251–259 (1971).
[Crossref] [PubMed]

N. Graham, “Psychophysics of spatial-frequency channels,” in Perceptual Organization, M. Kubovy, J. Pomerantz, eds. (Erlbaum Halstead, Potomac, Md., 1980), pp. 1–25.

Henning, G. B.

Hertz, B. G.

Hinton, J. L.

Julesz, B.

Klein, S.

C. F. Strohmeyer, S. Klein, B. M. Dawson, L. Spillmann, “Low spatial-frequency channels in human vision: adaption and masking,” Vision Res. 22, 225–233 (1982).
[Crossref]

C. F. Strohmeyer, S. Klein, “Evidence against narrow-band spatial frequency channels in human vision: the detectability of frequency modulated gratings,” Vision Res. 15, 899–910 (1975).
[Crossref]

Klopfenstein, R. W.

Landy, M.

G. Sperling, M. Landy, Y. Cohen, M. Pavel, “Intelligible encoding of ASL image sequences at extremely low information rates,” Comput. Vision Graph. Image Process. 31, 335–391 (1985).
[Crossref]

Lange, R. V.

S. Stecher, C. Sigel, R. V. Lange, “Composite adaptation and spatial frequency interactions,” Vision Res. 13, 2527–2531 (1973).
[Crossref] [PubMed]

Legge, G.

Legge, G. E.

G. E. Legge, D. G. Pelli, G. S. Rubin, M. M. Schleske, “Psycho-physics of reading—I. Normal vision,” Vision Res. 25, 239–252 (1985).
[Crossref]

Nachmias, J.

J. Nachmias, A. Wever, “Discrimination of simple and complex gratings,” Vision Res. 15, 217–223 (1975).
[Crossref] [PubMed]

J. Nachmias, R. V. Sansbury, “Grating contrast: discrimination maybe better than detection,” Vision Res. 14, 1039–1042 (1974).
[Crossref] [PubMed]

N. Graham, J. Nachmias, “Detection of grating patterns containing two spatial frequencies: a comparison of single-channel and multiple models,” Vision Res. 11, 251–259 (1971).
[Crossref] [PubMed]

Olzak, L. A.

For a review, see L. A. Olzak, J. P. Thomas, “Seeing spatial patterns,” in Handbook of Perception and Performance, K. R. Boff, L. Kaufman, J. P. Thomas, eds. (Wiley, New York, 1986), Chap. 7.

Parish, D. H.

D. H. Parish, G. Sperling, “Object spatial frequency, not retinal spatial frequency, determines identification efficiency,” Invest. Ophthalmol. Vis. Sci. Suppl. 28, 359 (1987).

G. Sperling, D. H. Parish, “Object spatial frequencies, retinal spatial frequencies, noise, and the efficiency of discrimination,” in Mathematical Studies in Perception and Cognition (Department of Psychology, New York University, New York, N.Y., 1987).

Pavel, M.

M. Pavel, G. Sperling, T. Riedl, A. Vanderbeek, “Limits of visual communication: the effects of signal-to-noise ratio on the intelligibility of American Sign Language,” J. Opt. Soc. Am. A 4, 2355–2365 (1987).
[Crossref] [PubMed]

G. Sperling, M. Landy, Y. Cohen, M. Pavel, “Intelligible encoding of ASL image sequences at extremely low information rates,” Comput. Vision Graph. Image Process. 31, 335–391 (1985).
[Crossref]

Pelli, D. G.

G. E. Legge, D. G. Pelli, G. S. Rubin, M. M. Schleske, “Psycho-physics of reading—I. Normal vision,” Vision Res. 25, 239–252 (1985).
[Crossref]

D. G. Pelli, “Effects of visual noise,” doctoral dissertation (University of Cambridge, Cambridge, 1981).

Riedl, T.

Riedl, T. R.

T. R. Riedl, “Spatial frequency selectivity and higher level human information processing,” doctoral dissertation (New York University, New York, N.Y., 1985).

Rubin, G. S.

G. E. Legge, D. G. Pelli, G. S. Rubin, M. M. Schleske, “Psycho-physics of reading—I. Normal vision,” Vision Res. 25, 239–252 (1985).
[Crossref]

Sansbury, R. V.

J. Nachmias, R. V. Sansbury, “Grating contrast: discrimination maybe better than detection,” Vision Res. 14, 1039–1042 (1974).
[Crossref] [PubMed]

Schein, J. D.

J. D. Schein, M. T. Delk, The Deaf Population of the United States (National Association of the Deaf, Silver Spring Md., 1974).

Schleske, M. M.

G. E. Legge, D. G. Pelli, G. S. Rubin, M. M. Schleske, “Psycho-physics of reading—I. Normal vision,” Vision Res. 25, 239–252 (1985).
[Crossref]

Sigel, C.

S. Stecher, C. Sigel, R. V. Lange, “Composite adaptation and spatial frequency interactions,” Vision Res. 13, 2527–2531 (1973).
[Crossref] [PubMed]

Sperling, G.

M. Pavel, G. Sperling, T. Riedl, A. Vanderbeek, “Limits of visual communication: the effects of signal-to-noise ratio on the intelligibility of American Sign Language,” J. Opt. Soc. Am. A 4, 2355–2365 (1987).
[Crossref] [PubMed]

D. H. Parish, G. Sperling, “Object spatial frequency, not retinal spatial frequency, determines identification efficiency,” Invest. Ophthalmol. Vis. Sci. Suppl. 28, 359 (1987).

G. Sperling, M. Landy, Y. Cohen, M. Pavel, “Intelligible encoding of ASL image sequences at extremely low information rates,” Comput. Vision Graph. Image Process. 31, 335–391 (1985).
[Crossref]

G. Sperling, “Video transmission of American Sign Language and finger spelling: present and projected bandwidth requirements,” IEEE Trans. Commun. COM-29, 1993–2002 (1981).
[Crossref]

G. Sperling, “Bandwidth requirements for video transmission of American Sign Language and finger spelling,” Science 210, 797–799 (1980).
[Crossref] [PubMed]

G. Sperling, D. H. Parish, “Object spatial frequencies, retinal spatial frequencies, noise, and the efficiency of discrimination,” in Mathematical Studies in Perception and Cognition (Department of Psychology, New York University, New York, N.Y., 1987).

Spillmann, L.

C. F. Strohmeyer, S. Klein, B. M. Dawson, L. Spillmann, “Low spatial-frequency channels in human vision: adaption and masking,” Vision Res. 22, 225–233 (1982).
[Crossref]

Stecher, S.

S. Stecher, C. Sigel, R. V. Lange, “Composite adaptation and spatial frequency interactions,” Vision Res. 13, 2527–2531 (1973).
[Crossref] [PubMed]

Strohmeyer, C. F.

C. F. Strohmeyer, S. Klein, B. M. Dawson, L. Spillmann, “Low spatial-frequency channels in human vision: adaption and masking,” Vision Res. 22, 225–233 (1982).
[Crossref]

C. F. Strohmeyer, S. Klein, “Evidence against narrow-band spatial frequency channels in human vision: the detectability of frequency modulated gratings,” Vision Res. 15, 899–910 (1975).
[Crossref]

C. F. Strohmeyer, B. Julesz, “Spatial-frequency masking in vision: critical bands and spread of masking,” J. Opt. Soc. Am. 62, 1221–1232 (1972).
[Crossref]

Thomas, J. P.

For a review, see L. A. Olzak, J. P. Thomas, “Seeing spatial patterns,” in Handbook of Perception and Performance, K. R. Boff, L. Kaufman, J. P. Thomas, eds. (Wiley, New York, 1986), Chap. 7.

Tolhurst, D. J.

D. J. Tolhurst, L. P. Barfield, “Interactions between spatial frequency channels,” Vision Res. 18, 951–958 (1978).
[Crossref] [PubMed]

D. J. Tolhurst, “Adaptation to square-wave gratings: inhibition between spatial frequency channels in the human visual system,” J. Physiol. 226, 231–248 (1972).
[PubMed]

Vanderbeek, A.

Wever, A.

J. Nachmias, A. Wever, “Discrimination of simple and complex gratings,” Vision Res. 15, 217–223 (1975).
[Crossref] [PubMed]

Wilson, H. R.

H. R. Wilson, J. R. Bergen, “A four mechanism model for threshold spatial vision,” Vision Res. 19, 19–32 (1979).
[Crossref] [PubMed]

Comput. Vision Graph. Image Process. (1)

G. Sperling, M. Landy, Y. Cohen, M. Pavel, “Intelligible encoding of ASL image sequences at extremely low information rates,” Comput. Vision Graph. Image Process. 31, 335–391 (1985).
[Crossref]

IEEE Trans. Commun. (2)

P. J. Burt, E. H. Adelson, “The Laplacian pyramid as a compact image code,” IEEE Trans. Commun. COM-31, 532–540 (1983).
[Crossref]

G. Sperling, “Video transmission of American Sign Language and finger spelling: present and projected bandwidth requirements,” IEEE Trans. Commun. COM-29, 1993–2002 (1981).
[Crossref]

Invest. Ophthalmol. Vis. Sci. Suppl. (1)

D. H. Parish, G. Sperling, “Object spatial frequency, not retinal spatial frequency, determines identification efficiency,” Invest. Ophthalmol. Vis. Sci. Suppl. 28, 359 (1987).

J. Opt. Soc. Am. (3)

J. Opt. Soc. Am. A (3)

J. Physiol. (1)

D. J. Tolhurst, “Adaptation to square-wave gratings: inhibition between spatial frequency channels in the human visual system,” J. Physiol. 226, 231–248 (1972).
[PubMed]

Science (1)

G. Sperling, “Bandwidth requirements for video transmission of American Sign Language and finger spelling,” Science 210, 797–799 (1980).
[Crossref] [PubMed]

Vision Res. (9)

G. E. Legge, D. G. Pelli, G. S. Rubin, M. M. Schleske, “Psycho-physics of reading—I. Normal vision,” Vision Res. 25, 239–252 (1985).
[Crossref]

H. R. Wilson, J. R. Bergen, “A four mechanism model for threshold spatial vision,” Vision Res. 19, 19–32 (1979).
[Crossref] [PubMed]

C. F. Strohmeyer, S. Klein, B. M. Dawson, L. Spillmann, “Low spatial-frequency channels in human vision: adaption and masking,” Vision Res. 22, 225–233 (1982).
[Crossref]

S. Stecher, C. Sigel, R. V. Lange, “Composite adaptation and spatial frequency interactions,” Vision Res. 13, 2527–2531 (1973).
[Crossref] [PubMed]

J. Nachmias, R. V. Sansbury, “Grating contrast: discrimination maybe better than detection,” Vision Res. 14, 1039–1042 (1974).
[Crossref] [PubMed]

C. F. Strohmeyer, S. Klein, “Evidence against narrow-band spatial frequency channels in human vision: the detectability of frequency modulated gratings,” Vision Res. 15, 899–910 (1975).
[Crossref]

J. Nachmias, A. Wever, “Discrimination of simple and complex gratings,” Vision Res. 15, 217–223 (1975).
[Crossref] [PubMed]

D. J. Tolhurst, L. P. Barfield, “Interactions between spatial frequency channels,” Vision Res. 18, 951–958 (1978).
[Crossref] [PubMed]

N. Graham, J. Nachmias, “Detection of grating patterns containing two spatial frequencies: a comparison of single-channel and multiple models,” Vision Res. 11, 251–259 (1971).
[Crossref] [PubMed]

Other (7)

N. Graham, “Psychophysics of spatial-frequency channels,” in Perceptual Organization, M. Kubovy, J. Pomerantz, eds. (Erlbaum Halstead, Potomac, Md., 1980), pp. 1–25.

D. G. Pelli, “Effects of visual noise,” doctoral dissertation (University of Cambridge, Cambridge, 1981).

J. P. Chandler, “stepit,” in Quantum Chemistry Program Exchange (Department of Chemistry, Indiana University, Bloomington, Ind., 1965).

T. R. Riedl, “Spatial frequency selectivity and higher level human information processing,” doctoral dissertation (New York University, New York, N.Y., 1985).

For a review, see L. A. Olzak, J. P. Thomas, “Seeing spatial patterns,” in Handbook of Perception and Performance, K. R. Boff, L. Kaufman, J. P. Thomas, eds. (Wiley, New York, 1986), Chap. 7.

G. Sperling, D. H. Parish, “Object spatial frequencies, retinal spatial frequencies, noise, and the efficiency of discrimination,” in Mathematical Studies in Perception and Cognition (Department of Psychology, New York University, New York, N.Y., 1987).

J. D. Schein, M. T. Delk, The Deaf Population of the United States (National Association of the Deaf, Silver Spring Md., 1974).

Cited By

OSA participates in Crossref's Cited-By Linking service. Citing articles from OSA journals and other participating publishers are listed here.

Alert me when this article is cited.


Figures (13)

Fig. 1
Fig. 1

Gain versus frequency for the filters used to create the spatial bandpass stimuli. Frequency is in log2 (cycles per frame width). Upper graphs represent the filters used for the initial investigation (experiment la); lower graphs represent the filters used in experiment lb and all subsequent experiments. The numbers 1–4 are used to designate the filter bands.

Fig. 2
Fig. 2

The ASL images filtered in bands 1–4. The leftmost image is the unfiltered original.

Fig. 3
Fig. 3

Intelligibility (percentage of correct ASL sign identifications) as a function of the spatial-frequency band. Curve labeled INITIAL was obtained in experiment la with the filter set at top of Fig. 1; curve labeled FINAL was obtained in experiment lb with filters at the bottom of Fig. 1 and with improved stimuli.

Fig. 4
Fig. 4

The temporal power spectrum of ASL in spatial-frequency bands 1–4. The abcissa represents the temporal frequency in hertz; the maximum frequency of 15 Hz is determined by the frame rate of 30 Hz. The ordinate represents the average power in an annular band of temporal frequencies extracted from a three-dimensional (x, y, t) Fourier analysis of eight representative ASL sign sequences. The line of slope −1 is drawn for reference.

Fig. 5
Fig. 5

Examples of all combinations of band-filtered signals plus band-filtered noise, a, Gaussian noise filtered in bands 1–4 (left to right). b, Band-filtered ASL signals plus band-filtered noise. Each row represents a single signal band with band 1 at the top and band 4 on the bottom. Each column (continuing downward from a) represents a single band of Gaussian noise. The leftmost column represents the noise-free signal.

Fig. 6
Fig. 6

Average ratings as a function of signal-to-noise ratio for the signal and the noise in band 3. The data are indicated by circles; the three-segment fit is indicated by the heavy lines. The dashed lines indicate the procedure for estimating (s/n)50%, the abscissa value under the arrow.

Fig. 7
Fig. 7

Rating functions for cross-band masking. The abscissa is the signal-to-noise ratio; the ordinate is the mean rating, and the curves represent the three-segment best fits to the data. Each panel represents data from one signal band si; the curve label indicates the band of the noise nj.

Fig. 8
Fig. 8

Masking effectiveness of noise bands against signal bands. The abscissa is the signal band si; the ordinate is the value of (s/n)50 derived from the rating functions (Fig. 7) by the estimation procedure shown in Fig. 6. The curve parameter indicates the noise band. Emphasized points indicate that the signal and the noise are in the same band.

Fig. 9
Fig. 9

Normalized cross-band masking as a function of frequency separation. Each band is represented by its mean frequency f. The abscissa represents the log2 of fsignal/fnoise. The ordinate is the log2 of the normalized masking effectiveness, the same data as in Fig. 8 with the curves for each signal band i moved up so that (si/ni)50% falls at 0.0. Signal bands i and noise bands j are indicated by i + j; the center of the + indicates the plotted datum. The straight lines represent the optimal mirror-symmetric fit to the data; the lines are centered above log2(fs/fn) = 0.46 and with a slope of ±1.11.

Fig. 10
Fig. 10

Spatial power spectrum of the composite noise used in experiment 4. The abscissa is the log2 of the spatial frequency in cycles per picture width (f0, the width, is 64 pixels). The extreme-left-hand side represents 1 cycle per picture; the extreme-right-hand side represents 32 cycles per picture. The ordinate represents relative power on a linear scale.

Fig. 11
Fig. 11

Single frames illustrating the stimuli for experiment 4: The sum of weak signals in bands i and j plus the composite noise of Fig. 10. Composite noise is equally present in all stimuli. The leftmost column represents single-band signals, with the band indicated by the number at the left. The other panels represent stimuli composed of two signal bands, one component band indicated by the number at the left of the row and the other band indicated by the number at the top of the column.

Fig. 12
Fig. 12

Data from experiment 4: Intelligibility of band-limited single-band signals in composite noise. The abscissa indicates the band of the signal; the ordinate indicates the percent correct scored by the 16 subjects in the intelligibility test. The curve parameter indicates the signal-to-noise ratio of the stimuli. The curve labeled ∞ represents data obtained without added noise in experiment 1 (with different subjects and a slightly different stimulus set). On the left-hand ordinate, the point S1−4 indicates intelligibility of the noise-free sum signal of band 1 + band 2 + band 3 + band 4; the point S1−4+N indicates the intelligibility of the same signal plus noise (s/n = 1).

Fig. 13
Fig. 13

Data from experiment 4: intelligibility of pairs of band-limited signals in composite noise. The ordinate, the abscissa, and the curves labeled 0.25 and ∞ are as in Fig. 12. The dashed curves indicate signals composed of band i (indicated on abscissa) and band j (indicated as the curve parameter). The open circles represent data for i = j, the middle curve of Fig. 12. The flat diamonds represent the addition of nearby signal bands (2 and 3); the tall diamonds represent the addition of distant bands (1 and 4). The pairs indicated by diamonds are matched for the strengths of their constituent signals.

Tables (1)

Tables Icon

Table 1 Filter Parameters in Cycles per Frame Widtha and the Measured Intelligibility of the Filtered ASL Signs

Equations (4)

Equations on this page are rendered with MathJax. Learn more.

NME ( s i / n j ) = ( s i / n j ) 50 % / ( s i / n i ) 50 % .
y i , j , k = m + c i + s j + a k + i , j , k .
c i = 1 16 j = 1 16 y i , j , k m = 1 16 k = 1 16 y i , j , k m ,
LP K ( ω x , ω y , σ x , σ y ) = exp [ 2 π 2 ( σ x 2 ω x 2 + σ y 2 ω y 2 ) ] ,

Metrics