Professor John F Culling, School of Psychology, Cardiff University

Overview

Research Group: Perception & Action
Location: Tower Building, Park Place
Email: CullingJ@cardiff.ac.uk
Telephone: +44(0)29 208 74523

Research Summary

Listeners are highly proficient at detecting and identifying sounds, especially speech sounds, in background noise. This ability is remarkable, because the waveform of the attended voice may be quite swamped by those of competing voices at the two ears. It also has important practical ramifications, since hearing impaired listeners often find a single voice intelligible when amplified, but find any interfering sound intolerable. In very noise environments normally-hearing listeners will also struggle, especially in reverberant rooms. By investigating the perceptual mechanisms which underlie these effects, I hope to uncover principles which could guide the design of hearing-aids, cochlear implants and, indeed, rooms so that they facilitate rather than impede communication in noise.

Teaching Summary

I teach Normal and Impaired Hearing at level 3 (PS3308). My lectures examine the auditory system from a mainly psychoacoustic perspective, explaining how the functions of the cochlea and brain can be elucidated purely through listening experiments. The physiology of the ear is mainly presented towards the end of the lecture series as an introduction to the effects hearing impairment and nature of the hearing facilitated by cochlear implantation. I also supervise level 2 practicals in perception, focussing on the parameters of the human voice, their sexual differentiation and the potential influence of these parameters on vocal attractiveness.

Selected Publications (2008 onwards)

2013

Culling, J. F. and Mansell, E. R. (2013). Speech intelligibility among modulated and spatially distributed noise sources. Journal of the Acoustical Society of America, 133(4), 2254-2261. (10.1121/1.4794384)

2012

Culling, J. F., Jelfs, S., Talbert, A., Grange, J. and Backhouse, S. S. (2012). The benefit of bilateral versus unilateral cochlear implantation to speech intelligibility in noise. Ear and Hearing, 33(6), 673-683. (10.1097/AUD.0b013e3182587356)

Lavandier, M. N., Jelfs, S., Culling, J. F., Watkins, A. J., Raimond, A. P. and Makin, S. J. (2012). Binaural prediction of speech intelligibility in reverberant rooms with multiple noise sources. The Journal of the Acoustical Society of America (JASA), 131(1), 218-231. (10.1121/1.3662075)

2011

Culling, J. F. (2011). Subcomponent cues in binaural unmasking. Journal of the Acoustical Society of America, 129(6), 3846-3855. (10.1121/1.3560944)

Deroche, M. L. D. and Culling, J. F. (2011). Narrow noise band detection in a complex masker: Masking level difference due to harmonicity. Hearing Research, 282(1-2), 225-235. (10.1016/j.heares.2011.07.005)

Deroche, M. L. D. and Culling, J. F. (2011). Voice segregation by difference in fundamental frequency: Evidence for harmonic cancellation. The Journal of the Acoustical Society of America (JASA), 130(5), 2855-2865. (10.1121/1.3643812)

Ishak, W. S., Zhao, F., Stephens, D., Culling, J. F., Bai, Z. and Meyer-Bisch, C. (2011). Test-retest reliability and validity of Audioscan and Békésy compared with pure tone audiometry. Audiological Medicine, 9(1), 40-46. (10.3109/1651386X.2010.537124)

Jelfs, S., Culling, J. F. and Lavandier, M. N. (2011). Revision and validation of a binaural model for speech intelligibility in noise. Hearing Research, 275(1-2), 96-104. (10.1016/j.heares.2010.12.005)

2010

Culling, J. F. (2010). Subcomponent cues in binaural unmasking. In: Lopez-Poveda, E., Palmer, A. and Meddis, R. eds. The Neurophysiological Bases of Auditory Perception. London: Springer, pp. 247-255. (10.1007/978-1-4419-5686-6_23)

Culling, J. F. and Lewis, H. G. (2010). Trading of intensity and interaural coherence in dichotic pitch stimuli. Journal of the Acoustical Society of America, 128(4), 1908-1914. (10.1121/1.3478853)

Kolarik, A. J. and Culling, J. F. (2010). Measurement of the binaural auditory filter using a detection task. The Journal of the Acoustical Society of America (JASA), 127(5), 3009-3017. (10.1121/1.3365314)

Lavandier, M. N. and Culling, J. F. (2010). Prediction of binaural speech intelligibility against noise in rooms. The Journal of the Acoustical Society of America, 127(1), 387-399. (10.1121/1.3268612)

2009

Edmonds, B. A. and Culling, J. F. (2009). Interaural correlation and the binaural summation of loudness. Journal of the Acoustical Society of America, 125(6), 3865-3870. (10.1121/1.3120412)

Kolarik, A. J. and Culling, J. F. (2009). Measurement of the binaural temporal window using a lateralisation task. Hearing Research, 248(1-2), 60-68. (10.1016/j.heares.2008.12.001)

Kolarik, A. J. and Culling, J. F. (2009). The masking of interaural delays. The Journal of the Acoustical Society of America (JASA), 125(4), 2162-2171. (10.1121/1.3083238)

2008

Lavandier, M. N. and Culling, J. F. (2008). Speech segregation in rooms: monaural, binaural, and interacting effects of reverberation on target and interferer. Journal of the Acoustical Society of America, 123(4), 2237-2248. (10.1121/1.2871943 )

Publications

Online Publications

Online information about my publications can be obtained via Google Scholar or ResearcherID:

Full List of Publications

Forthcoming

2013

Culling, J. F. and Mansell, E. R. (2013). Speech intelligibility among modulated and spatially distributed noise sources. Journal of the Acoustical Society of America, 133(4), 2254-2261. (10.1121/1.4794384)

2012

Culling, J. F., Jelfs, S., Talbert, A., Grange, J. and Backhouse, S. S. (2012). The benefit of bilateral versus unilateral cochlear implantation to speech intelligibility in noise. Ear and Hearing, 33(6), 673-683. (10.1097/AUD.0b013e3182587356)

Lavandier, M. N., Jelfs, S., Culling, J. F., Watkins, A. J., Raimond, A. P. and Makin, S. J. (2012). Binaural prediction of speech intelligibility in reverberant rooms with multiple noise sources. The Journal of the Acoustical Society of America (JASA), 131(1), 218-231. (10.1121/1.3662075)

2011

Culling, J. F. (2011). Subcomponent cues in binaural unmasking. Journal of the Acoustical Society of America, 129(6), 3846-3855. (10.1121/1.3560944)

Deroche, M. L. D. and Culling, J. F. (2011). Narrow noise band detection in a complex masker: Masking level difference due to harmonicity. Hearing Research, 282(1-2), 225-235. (10.1016/j.heares.2011.07.005)

Deroche, M. L. D. and Culling, J. F. (2011). Voice segregation by difference in fundamental frequency: Evidence for harmonic cancellation. The Journal of the Acoustical Society of America (JASA), 130(5), 2855-2865. (10.1121/1.3643812)

Ishak, W. S., Zhao, F., Stephens, D., Culling, J. F., Bai, Z. and Meyer-Bisch, C. (2011). Test-retest reliability and validity of Audioscan and Békésy compared with pure tone audiometry. Audiological Medicine, 9(1), 40-46. (10.3109/1651386X.2010.537124)

Jelfs, S., Culling, J. F. and Lavandier, M. N. (2011). Revision and validation of a binaural model for speech intelligibility in noise. Hearing Research, 275(1-2), 96-104. (10.1016/j.heares.2010.12.005)

2010

Culling, J. F. (2010). Subcomponent cues in binaural unmasking. In: Lopez-Poveda, E., Palmer, A. and Meddis, R. eds. The Neurophysiological Bases of Auditory Perception. London: Springer, pp. 247-255. (10.1007/978-1-4419-5686-6_23)

Culling, J. F. and Lewis, H. G. (2010). Trading of intensity and interaural coherence in dichotic pitch stimuli. Journal of the Acoustical Society of America, 128(4), 1908-1914. (10.1121/1.3478853)

Kolarik, A. J. and Culling, J. F. (2010). Measurement of the binaural auditory filter using a detection task. The Journal of the Acoustical Society of America (JASA), 127(5), 3009-3017. (10.1121/1.3365314)

Lavandier, M. N. and Culling, J. F. (2010). Prediction of binaural speech intelligibility against noise in rooms. The Journal of the Acoustical Society of America, 127(1), 387-399. (10.1121/1.3268612)

2009

Edmonds, B. A. and Culling, J. F. (2009). Interaural correlation and the binaural summation of loudness. Journal of the Acoustical Society of America, 125(6), 3865-3870. (10.1121/1.3120412)

Kolarik, A. J. and Culling, J. F. (2009). Measurement of the binaural temporal window using a lateralisation task. Hearing Research, 248(1-2), 60-68. (10.1016/j.heares.2008.12.001)

Kolarik, A. J. and Culling, J. F. (2009). The masking of interaural delays. The Journal of the Acoustical Society of America (JASA), 125(4), 2162-2171. (10.1121/1.3083238)

2008

Lavandier, M. N. and Culling, J. F. (2008). Speech segregation in rooms: monaural, binaural, and interacting effects of reverberation on target and interferer. Journal of the Acoustical Society of America, 123(4), 2237-2248. (10.1121/1.2871943 )

2007

Binns, C. and Culling, J. F. (2007). The role of fundamental frequency contours in the perception of speech against interfering speech. Journal of the Acoustical Society of America, 122(3), 1765-1776. (10.1121/1.2751394)

Culling, J. F. (2007). Evidence specifically favoring the equalization-cancellation theory of binaural unmasking. Journal of the Acoustical Society of America, 122(5), 2803-2813. (10.1121/1.2785035)

Lavandier, M. N. and Culling, J. F. (2007). Speech segregation in rooms: effects of reverberation on both target and interferer. Journal of the Acoustical Society of America, 122(3), 1713-1723. (10.1121/1.2764469)

2006

Culling, J. F., Edmonds, B. A. and Hodder, K. I. (2006). Speech perception from monaural and binaural information. The Journal of the Acoustical Society of America (JASA), 119, 559-565. (10.1121/1.2140806)

Edmonds, B. A. and Culling, J. F. (2006). The spatial unmasking of speech: Evidence for better-ear listening. Journal of the Acoustical Society of America, 120(3), 1539-1545. (10.1121/1.2228573)

2005

Culling, J. F., Zhao, F. and Stephens, D. (2005). The viability of speech-in-noise audiometric screening using domestic audio equipment. International Journal of Audiology, 44(12), 691-700. (10.1080/14992020500267017)

Edmonds, B. A. and Culling, J. F. (2005). 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(3), 546-553.

Edmonds, B. A. and Culling, J. F. (2005). The spatial unmasking of speech: Evidence for within-channel processing of interaural time delay. Journal of the Acoustical Society of America, 117(5), 3069-3078. (10.1121/1.1880752)

2004

Culling, J. F., Hawley, M. L. and Litovsky, R. Y. (2004). The role of head-induced interaural time and level differences in the speech reception threshold for multiple interfering sound sources. Journal of the Acoustical Society of America, 116(2), 1057-1065. (10.1121/1.1772396)

Hawley, M. L., Litovsky, R. Y. and Culling, J. F. (2004). The benefit of binaural hearing in a cocktail party: Effect of location and type of interferer. Journal of the Acoustical Society of America, 115(2), 833-843. (10.1121/1.1639908)

2003

Culling, J., Hodder, K. I. and Colburn, H. S. (2003). Interaural correlation discrimination with spectrally-remote flanking noise: Constraints for models of binaural unmasking. Acta Acustica united with Acustica, 89(6), 1049-1058.

Culling, J. F., Hodder, K. I. and Toh, C. Y. (2003). Effects of reverberation on perceptual segregation of competing voices. Journal of the Acoustical Society of America, 114, 2871-2876. (10.1121/1.1616922)

2001

Culling, J. F., Colburn, H. S. and Spurchise, M. (2001). Interaural correlation sensitivity. Journal of the Acoustical Society of America, 110, 1020-1029. (10.1121/1.1383296)

2000

Culling, J. F. (2000). Auditory motion segregation: a limited analogy with vision. Journal of Experimental Psychology: Human Perception and Performance, 26(6), 1760-1769.

Culling, J. F. and Colburn, H. S. (2000). Binaural sluggishness in the perception of tone sequences and speech in noise. Journal of the Acoustical Society of America, 107(1), 517-527. (10.1121/1.428320)

Culling, J. F. (2000). Dichotic pitches as illusions of binaural unmasking. III. The existence region of the Fourcin pitch. Journal of the Acoustical Society of America, 107(4), 2201-2208. (10.1121/1.428500)

1999

Culling, J. F. (1999). The existence region of Huggins' pitch. Hearing Research, 127(1-2), 143-148. (10.1016/S0378-5955(98)00193-2)

1998

Culling, J. F., Summerfield, A. Q. and Marshall, D. H. (1998). Dichotic pitches as illusions of binaural unmasking. I. Huggins' pitch and the "binaural edge pitch". Journal of the Acoustical Society of America, 103(6), 3509-3526. (10.1121/1.423059)

Culling, J. F., Marshall, D. H. and Summerfield, Q. (1998). Dichotic pitches as illusions of binaural unmasking. II. The Fourcin pitch and the dichotic repetition pitch. Journal of the Acoustical Society of America, 103(6), 3527-3539. (10.1121/1.423060)

Culling, J. F. and Summerfield, Q. (1998). Measurements of the binaural temporal window using a detection task. Journal of the Acoustical Society of America, 103(6), 3540-3553. (10.1121/1.423061 )

Mossop, J. E. and Culling, J. F. (1998). The lateralization of large interaural delays. Journal of the Acoustical Society of America, 104(3), 1574-1579.

Culling, J. F. and Summerfield, Q. (1995). The role of frequency modulation in the perceptual segregation of concurrent vowels. Journal of the Acoustical Society of America, 98(2), 837-846. (10.1121/1.413510)

1994

Culling, J. and Darwin, C. J. (1994). Perceptual and computational separation of simultaneous vowels: cues arising from low-frequency beating. Journal of the Acoustical Society of America, 95(3), 1559-1569. (10.1121/1.408543)

Culling, J. F., Summerfield, Q. and Marshall, D. H. (1994). Effects of simulated reverberation on the use of binaural cues and fundamental-frequency differences for separating concurrent vowels. Speech Communication, 14(1), 71-95. (10.1016/0167-6393(94)90058-2)

1993

Culling, J. F. and Darwin, C. J. (1993). Perceptual separation of concurrent vowels: within and across-formant grouping by F0. Journal of the Acoustical Society of America, 93(6), 3456-3467.

Culling, J. F. and Darwin, C. J. (1993). The role of timbre in the segregation of simultaneous voices with intersecting F0 contours. Perception & psychophysics, 54(3), 303-309. (10.3758/BF03205265 )

1992

Summerfield, Q., Culling, J. F. and Fourcin, A. J. (1992). Auditory segregation of competing voices: absence of effects of FM or AM coherence [and discussion]. Philosophical Transactions of the Royal Society of London Series B - Biological Sciences, 336(1278), 357-366. (10.1098/rstb.1992.0069)

1990

Darwin, C. J. and Culling, J. F. (1990). Speech perception seen through the ear. Speech Communication, 9(5-6), 469-475. (10.1016/0167-6393(90)90022-2)

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Research

Research Topics and Related Papers

My research focuses on the cocktail-party problem, which concerns how listeners are able to cope with high levels of interfering noise when listening to speech. Typically, such interfering noise may consist of many other competing voices, as at a cocktail party or a busy restaurant. Humans (and other animals) remain far more proficient at this task than any automatic system. They are known to use many different mechanisms, all of which fall within my research interests, but most of my research concerns binaural hearing.

Much of my early work was concerned with differences in F0 (DF0s). I found that the effect of DF0s operates principally in the first formant region (Culling and Darwin, 1993), and that DF0s produce multiple perceptual cues, including amplitude modulations (Culling and Darwin, 1994). Differences in modulation of F0 were only useful when that modulation introduced a difference in F0 (Darwin and Culling, 1990).

Through the possession of two ears listeners are able to exploit differences in sound source location. The effect involves interaural level differences (ILDs) and interaural time differences (ITDs), the cues used for left/right sound localisation (Culling et al., 2004). However, distinct perceived locations for target and interfering sound are not necessary or sufficient for listeners to perceptually separate competing sounds. Culling and Summerfield (1995) found that listeners were unable to perceptually segregate a whispered vowel, represented by two noise bands with a common ITD, from two concurrent (but spectrally distinct) noise bands with a different ITD. Edmonds and Culling (2005a) showed that speech need not have a consistent ITD in different frequency bands for listeners to perceptually segregate it from competing speech or noise, and that ITDs and ILDs need not even agree regarding source direction to get the full benefit of both cues (Edmonds and Culling 2005b).

Rather than relying on sound-source localisation, the binaural system seems to use a separate process, known as binaural unmasking. It has long been known that a signal can be detected or identified at a lower signal-to-noise ratio (SNR) if its interaural timing or phase differs from that of a masker. A similar effect is observed for the intelligibility of speech signals. One framework used to explain binaural unmasking is interaural cancellation, which was originally developed by Nat Durlach but which has lately been adapted for use with broadband signal such as speech (Culling and Summerfield, 1995; Culling et al. 2004; Lavandier and Culling, 2010). In this theory, the binaural system uses internally generated delays to compensate for the external delay of the masker and then subtracts the stimulus at one ear from that at the other. The predictions of this equalisation-cancellation (E-C) theory are almost indistinguishable from those derived using theories based on correlation, especially in their predictions of detection thresholds. However, Culling (2007) discovered that the two theories give increasingly divergent predictions at supra-threshold signal levels necessary for the more demanding task of speech understanding. Instead of using the typical task of requiring listeners to detect a signal in noise, Culling gave listeners a loudness discrimination task. The results were entirely consistent with E-C theory.

Binaural unmasking can also be used to explain a family of illusions known as dichotic pitches, which are generated purely by the interaural phase relationships (Culling et al., 1998a,b; Culling, 1999; Culling, 2000a,b).

Recently, I have been increasingly interested in the role of reverberation on the cocktail-party problem. Culling et al. (1994) employed virtual simulations rooms to measure the effect of reverberation upon spatial unmasking and upon the DF0 effect. Culling et al. presented synthesized ‘target’ vowel sounds against ‘masker’ vowels or pink noise, and listeners were required to identify the target vowels. In anechoic conditions, spatial separation of target and masker resulted in improved vowel-identification thresholds compared to when they were co-located, but in reverberation, this unmasking effect was abolished. Lavandier and Culling (2007, 2008) showed that the effect of reverberation on binaural unmasking is mediated by reduced interaural coherence of the masker. Reverberation also affected the intrinsic intelligibility of the target, but this effect occurred only at higher levels of reverberation.

Culling et al. (1994) also found that the effect of differences in F0 between competing vowels was robust in reverberation if the F0s of the two vowels were constant, but for modulated F0s, this effect was also abolished. This observation has considerable practical significance, because natural speech always has modulation in F0 from (among other things) its intonation. We are currently investigating the effects of reverberation on both theDF0 effect and spatial unmasking through an EPSRC grant.

Funding

EPSRC (£349K) “Effects of reverberation on conversation in rooms”

Research Group

Sam Jelfs (Ph.D. student, Psychology/Architecture, Cardiff University)

Research Collaborators

Dr Mike Fedeski (Architecture, Cardiff University).

Dr Tony Watkins (Psychology, University of Reading).

Dr Mathieu Lavandier (ENTPE, Université de Lyon)

Postgraduate Students

Postgraduate Research Interests

My current research interests focus around the cocktail-party problem and binaural hearing. Specific interests include binaural unmasking, dichotic pitches, speech perception in noise, perceptual segregation by differences in F0, dip listening, temporal and spectral resolution of the binaural system, and the effects of room reverberation.

If you are interested in applying for a PhD, or for further information regarding my postgraduate research, please contact me directly (contact details available on the 'Overview' page), or submit a formal application here.

Current Students

Sam Jelfs is jointly supervised by Dr Mike Fedeski from the Welsh School of Architecture. He is working on computationally efficient models of speech perception in noise in order to apply them to the acoustic design of rooms. He generates visualisations of speech intelligibility across a room – intelligibility maps. A target voice is placed a particular virtual position and masking noises at other positions, and a map is generated of the intelligibility that would be experienced at every point in the room.

Previous Students

Barrie Edmonds graduated with a Ph.D. in 2003. He worked on the role of across-freqeuncy processes in binaural segregation of speech in noise and against competing speech. He has since had post-doctoral positions with myself and with Dr. Katrin Krumbholz at the MRC Institute of Hearing Research. He is now a Lead Scientist at the National Biomedical Research Unit in Hearing.

Andrew Kolarik graduated with a Ph.D. in 2006. He worked on the temporal and spectral resolution of binaural unmasking. He has since had post-doctoral positions with myself and Dr Tom Freeman.

Christine Binns graduated with a Ph.D. in 2007. She worked on the role of intonation contours in speech perception in noise.

Mickael Deroche graduated with a Ph.D. in 2010. He worked on the effect of differences in F0 between competing voices on their intelligibility and the influence of room reverberation on this effect. He now has a post-doctoral position with Dr. Monita Chaterjee at the University of Maryland.

Biography

Undergraduate Education

did both my undergraduate degree in Experimental Psychology at Sussex. Following graduation I worked for several months with at the GEC Hirst Research Centre in Wembley on language processing software, before taking up a research assistantship with Dr. Ann Cutler at the MRC Applied Psychology Unit (now the Cognitive and Brain Sciences Unit). I worked there for a total of 16 months. While in Cambridge I also worked for six weeks on a phonetic labelling project in the Speech Laboratory of the Cambridge University Engineering Dept.

Postgradute Education

My doctoral thesis “The perception of double vowels” mainly concerned the effect of differences in fundamental frequency on listeners’ ability to perceptually separate concurrent speech. The experiments all involved simultaneous synthetic vowels with controlled fundamental frequency; where the vowels differed in fundamental frequency, the ability to identify both vowels in a pair was improved, suggesting that they had been perceptually separated prior to identification. The results indicated that the effect was predominantly mediated by low frequencies, but also that waveform interactions between the vowels played a substantial role. Other experiments investigate the effects of dynamic changes in fundamental frequency and in timbre.

Awards/External Committees

Fellow of the Hanse Wissenschaftskolleg.

Former member of the Perceptual and Physiological Acoustics Technical Committee of the Acoustical Society of America.

Employment

1991-1995 Short-term, non-clinical scientist, MRC Institute of Hearing Research

1995-1998 MRC Research Fellow, Dept. Physiology, Oxford University and Boston University.

1998-2003 Lecturer, School of Psychology, Cardiff University.

2003-2006 Senior Lecturer, School of Psychology, Cardiff University.

2006-2009 Reader, School of Psychology, Cardiff University.

2009- Professor, School of Psychology, Cardiff University.

School of Psychology

Professor John F Culling - BSc DPhil Sussex

Overview

Research Summary

Teaching Summary

Selected Publications (2008 onwards)

2013

2012

2011

2010

2009

2008

Publications

Online Publications

Full List of Publications

Forthcoming

2013

2012

2011

2010

2009

2008

2007

2006

2005

2004

2003

2001

2000

1999

1998

1997

1996

1995

1994

1993

1992

1990

Research

Research Topics and Related Papers

Funding

Research Group

Research Collaborators

Postgraduate Students

Postgraduate Research Interests

Current Students

Previous Students

Biography

Undergraduate Education

Postgradute Education

Awards/External Committees

Employment