The benefit of cochlear-implant users’ head orientation to speech intelligibility in noise


  • Jacques A. Grange Cardiff University, School of Psychology, Cardiff CF103AT, United Kingdom
  • John F. Culling Cardiff University, School of Psychology, Cardiff CF103AT, United Kingdom


Speech reception thresholds (SRTs) in noise improve when the speech and noise sources are spatially separated. This spatial release from masking (SRM) is usually investigated in fixed-head situations. We studied free-head situations in audio and audio-visual conditions. We compared normally- hearing and cochlear-implant (CI) users’ spontaneous and directed head- orientation strategies when attending to speech in noise with a progressively declining signal-to-noise ratio. SRM-model predictions suggested benefits of head orientation away from the target speech that we hypothesized would motivate head rotation. As signal-to-noise ratio declined, observed head tracks differed greatly between listeners. Audio-visual presentation reduced the amount of head rotation. When directed, listeners made more effective use of head rotation. Audio and audio-visual SRTs were acquired at fixed, 0, and 30 deg head orientations with respect to the target speech. At the most favourable 30-deg head orientation, SRM reached 8 and 6 dB for NH listeners and CI users respectively. Lip-reading yielded improvements of 3 and 5 dB on average across conditions. CI users confirmed that training in optimizing both their position and head orientation with respect to target speaker and noise source position in a social setting was both currently missing and likely valuable.


Bronkhorst, A., and Plomp, R. (1988). “The effect of head-induced interaural time and level differences on speech intelligibility in noise,” J. Acoust. Soc. Am., 83, 1508-1516.

Culling, J.F., Jelfs, S., Talbert, A., Grange, J.A, and Backhouse, S.S. (2012). “The benefit of bilateral versus unilateral cochlear implantation to speech intelligibility in noise,” Ear Hearing, 33, 673-682.

Jelfs, S., Culling, J.F., and Lavandier, M. (2011). “Revision and validation of a binaural model for speech intelligibility in noise,” Hear. Res., 275, 96-104.

Lavandier, M., and Culling, J.F. (2010). “Prediction of binaural speech intelligibility against noise in rooms,” J. Acoust. Soc. Am., 127, 387-399.

Litovsky, R.Y., Parkinson, A.J., Arcaroli, J., and Sammeth, C. (2006). “Simultaneous bilateral cochlear implantation in adults: A multicenter clinical study,” Ear Hearing, 27, 714-731.

Loizou, P.C., Hu, Y., Litovsky, R., Yu, G., Peters, R., Lake, J., and Roland, P. (2009). “Speech recognition by bilateral cochlear implant users in a cocktail- party setting,” J. Acoust. Soc. Am., 125, 372-383.

Schleich, P., Nopp, P., and D’Haese, P. (2004). “Head shadow, squelch, and summation effects in bilateral users of the MED-EL COMBI 40/40+ cochlear implant,” Ear Hearing, 25, 197-204.

Van Hoesel, R., and Tyler, R. (2003). “Speech perception, localization, and lateralization with bilateral cochlear implants,” J. Acoust. Soc. Am., 113, 1617- 1630.

Additional Files



How to Cite

Grange, J. A., & Culling, J. F. (2013). The benefit of cochlear-implant users’ head orientation to speech intelligibility in noise. Proceedings of the International Symposium on Auditory and Audiological Research, 4, 389–396. Retrieved from



2013/8. Factors influencing speech intelligibility