Formant-Frequency Variation and Its Effects on Across-Formant Grouping in Speech Perception

  • Brian Roberts
  • Robert J. Summers
  • Peter J. Bailey
Conference paper
Part of the Advances in Experimental Medicine and Biology book series (volume 787)

Abstract

How speech is separated perceptually from other speech remains poorly understood. In a series of experiments, perceptual organisation was probed by presenting three-formant (F1+F2+F3) analogues of target sentences dichotically, together with a competitor for F2 (F2C), or for F2+F3, which listeners must reject to optimise recognition. To control for energetic masking, the competitor was always presented in the opposite ear to the corresponding target formant(s). Sine-wave speech was used initially, and different versions of F2C were derived from F2 using separate manipulations of its amplitude and frequency contours. F2Cs with time-varying frequency contours were highly effective competitors, whatever their amplitude characteristics, whereas constant-frequency F2Cs were ineffective. Subsequent studies used synthetic-formant speech to explore the effects of manipulating the rate and depth of formant-frequency change in the competitor. Competitor efficacy was not tuned to the rate of formant-frequency variation in the target sentences; rather, the reduction in intelligibility increased with competitor rate relative to the rate for the target sentences. Therefore, differences in speech rate may not be a useful cue for separating the speech of concurrent talkers. Effects of competitors whose depth of formant-frequency variation was scaled by a range of factors were explored using competitors derived either by inverting the frequency contour of F2 about its geometric mean (plausibly speech-like pattern) or by using a regular and arbitrary frequency contour (triangle wave, not plausibly speech-like) matched to the average rate and depth of variation for the inverted F2C. Competitor efficacy depended on the overall depth of frequency variation, not depth relative to that for the other formants. Furthermore, the triangle-wave competitors were as effective as their more speech-like counterparts. Overall, the results suggest that formant-frequency variation is critical for the across-frequency grouping of formants but that this grouping does not depend on speech-specific constraints.

Keywords

Coherence 

Notes

Acknowledgements

This research was supported by Research Grant EP/F016484/1 from the Engineering and Physical Sciences Research Council (UK).

References

  1. Bailey PJ, Summerfield Q, Dorman M (1977) On the identification of sine-wave analogues of certain speech sounds. Haskins Lab Status Rep SR-51/52:1–25Google Scholar
  2. Boersma P, Weenink D (2010) Praat, a system for doing phonetics by computer. Institute of Phonetic Sciences, University of AmsterdamGoogle Scholar
  3. Bregman AS (1990) Auditory scene analysis: the perceptual organization of sound. MIT Press, CambridgeGoogle Scholar
  4. Darwin CJ (2008) Listening to speech in the presence of other sounds. Philos Trans R Soc Lond B Biol Sci 363:1011–1021PubMedCrossRefGoogle Scholar
  5. Mesgarani N, Chang EF (2012) Selective cortical representation of attended speaker in ­multi-talker speech perception. Nature 485:233–236PubMedCrossRefGoogle Scholar
  6. Remez RE (1996) Perceptual organization of speech in one and several modalities: common ­functions, common resources. In: ICSLP-1996, Philadelphia, p 1660–1663Google Scholar
  7. Remez RE, Rubin PE, Pisoni DB, Carrell TD (1981) Speech perception without traditional speech cues. Science 212:947–950PubMedCrossRefGoogle Scholar
  8. Remez RE, Rubin PE, Berns SM, Pardo JS, Lang JM (1994) On the perceptual organization of speech. Psychol Rev 101:129–156PubMedCrossRefGoogle Scholar
  9. Roberts B, Summers RJ, Bailey PJ (2010) The perceptual organization of sine-wave speech under competitive conditions. J Acoust Soc Am 128:804–817PubMedCrossRefGoogle Scholar
  10. Rosenberg AE (1971) Effect of glottal pulse shape on the quality of natural vowels. J Acoust Soc Am 49:583–590PubMedCrossRefGoogle Scholar
  11. Summers RJ, Bailey PJ, Roberts B (2012) Effects of the rate of formant-frequency variation on the grouping of formants in speech perception. J Assoc Res Otolaryngol 13:269–280PubMedCrossRefGoogle Scholar
  12. Weismer G, Berry J (2003) Effects of speaking rate on second formant trajectories of selected vocalic nuclei. J Acoust Soc Am 113: 3362–3378PubMedCrossRefGoogle Scholar

Copyright information

© Springer Science+Business Media New York 2013

Authors and Affiliations

  • Brian Roberts
    • 1
  • Robert J. Summers
    • 1
  • Peter J. Bailey
    • 2
  1. 1.Psychology, School of Life and Health SciencesAston UniversityBirminghamUK
  2. 2.Department of PsychologyUniversity of YorkHeslington, YorkUK

Personalised recommendations