Keck School Faculty

Robert Shannon, PhD
Robert Shannon, PhD
Professor of Research Otolaryngology-Head & Neck Surgery
Otolaryngology
1520 San Pablo Street Health Sciences Campus Los Angeles
I am interested in how auditory information is coded in the nervous system. My original research attempted to find common elements in physiological responses and perception of acoustic sound. Since 1977 my research has focused primarily on prosthetic electrical stimulation to restore hearing: cochlear implants, brainstem implants and midbrain implants. My research programs range from the biophysics and psychophysics of electrical stimulation of the auditory system, to speech pattern recognition and the design of signal processing for prosthetic devices. Research on auditory prostheses spans the fields of biomedical engineering, anatomy, physiology, psychophysics, perceptual object formation and pattern recognition. Artificial activation of a sensory system at different levels of processing can reveal the importance of various cues to auditory perception. The comparison of simple and complex perception between normal hearing and prosthetic activation of the cochlea, auditory brainstem and auditory midbrain gives insights into processing, storage and retrieval of auditory information in the nervous system.

Benefits of Cochlear Implantation for Single-Sided Deafness: Data From the House Clinic-University of Southern California-University of California, Los Angeles Clinical Trial Ear Hear. 2019 Jul/Aug; 40(4):766-781. . View in PubMed

Initial Results of a Safety and Feasibility Study of Auditory Brainstem Implantation in Congenitally Deaf Children Otol Neurotol. 2017 02; 38(2):212-220. . View in PubMed

Is Birdsong More Like Speech or Music? Trends Cogn Sci. 2016 Apr; 20(4):245-247.. View in PubMed

Consensus statement: Long-term results of ABI in children with complex inner ear malformations and decision making between CI and ABI Cochlear Implants Int. 2016 07; 17(4):163-171. . View in PubMed

Regulatory and funding strategies to develop a safety study of an auditory brainstem implant in young children who are deaf Ther Innov Regul Sci. 2015 Sep; 49(5):659-665. . View in PubMed

Two Laskers and Counting: Learning From the Past Enables Future Innovations With Central Neural Prostheses Brain Stimul. 2015 May-Jun; 8(3):439-41. . View in PubMed

Auditory implant research at the House Ear Institute 1989-2013 Hear Res. 2015 Apr; 322:57-66. . View in PubMed

Training improves cochlear implant rate discrimination on a psychophysical task J Acoust Soc Am. 2014 Jan; 135(1):334-41. . View in PubMed

The development of auditory perception in children after auditory brainstem implantation Audiol Neurootol. 2014; 19(6):386-94. . View in PubMed

Improving speech perception in noise with current focusing in cochlear implant users Hear Res. 2013 May; 299:29-36. . View in PubMed

Auditory brainstem implants for neurofibromatosis type 2 Curr Opin Otolaryngol Head Neck Surg. 2012 Oct; 20(5):353-7. . View in PubMed

Improving virtual channel discrimination in a multi-channel context Hear Res. 2012 Apr; 286(1-2):19-29. . View in PubMed

Histopathological analysis of a 15-year user of an auditory brainstem implant Laryngoscope. 2012 Mar; 122(3):645-8. . View in PubMed

Advances in auditory prostheses Curr Opin Neurol. 2012 Feb; 25(1):61-6. . View in PubMed

Estimated net saving to society from cochlear implantation in infants: a preliminary analysis Laryngoscope. 2011 Nov; 121(11):2455-60. . View in PubMed

Infants versus older children fitted with cochlear implants: performance over 10 years Int J Pediatr Otorhinolaryngol. 2011 Apr; 75(4):504-9. . View in PubMed

Effect of stimulation rate on cochlear implant users' phoneme, word and sentence recognition in quiet and in noise Audiol Neurootol. 2011; 16(2):113-23. . View in PubMed

Current focusing sharpens local peaks of excitation in cochlear implant stimulation Hear Res. 2010 Dec 01; 270(1-2):89-100. . View in PubMed

Complications in auditory brainstem implant surgery in adults and children Otol Neurotol. 2010 Jun; 31(4):558-64. . View in PubMed

Outcomes in nontumor adults fitted with the auditory brainstem implant: 10 years' experience Otol Neurotol. 2009 Aug; 30(5):614-8. . View in PubMed

Melodic contour identification and music perception by cochlear implant users Ann N Y Acad Sci. 2009 Jul; 1169:518-33. . View in PubMed

Beyond cochlear implants: awakening the deafened brain Nat Neurosci. 2009 Jun; 12(6):686-91. . View in PubMed

Evoked cortical activity and speech recognition as a function of the number of simulated cochlear implant channels Clin Neurophysiol. 2009 Apr; 120(4):776-82. . View in PubMed

Imaging in 28 children with cochlear nerve aplasia Acta Otolaryngol. 2009 Apr; 129(4):458-61. . View in PubMed

Progress in restoration of hearing with the auditory brainstem implant Prog Brain Res. 2009; 175:333-45. . View in PubMed

Audiologic outcomes with the penetrating electrode auditory brainstem implant Otol Neurotol. 2008 Dec; 29(8):1147-54. . View in PubMed

Auditory brainstem implants Neurotherapeutics. 2008 Jan; 5(1):128-36. . View in PubMed

Combined effects of frequency compression-expansion and shift on speech recognition Ear Hear. 2007 Jun; 28(3):277-89. . View in PubMed

The first successful case of hearing produced by electrical stimulation of the human midbrain Otol Neurotol. 2007 Jan; 28(1):39-43. . View in PubMed

Effects of stimulation mode, level and location on forward-masked excitation patterns in cochlear implant patients J Assoc Res Otolaryngol. 2006 Mar; 7(1):15-25. . View in PubMed

Frequency transposition around dead regions simulated with a noiseband vocoder J Acoust Soc Am. 2006 Feb; 119(2):1156-63. . View in PubMed

Effects of electrode design and configuration on channel interactions Hear Res. 2006 Jan; 211(1-2):33-45. . View in PubMed

Open set speech perception with auditory brainstem implant? Laryngoscope. 2005 Nov; 115(11):1974-8.. View in PubMed

Open set speech perception with auditory brainstem implant? Laryngoscope. 2005 Nov; 115(11):1974-8.. View in PubMed

Effects of stimulation rate on speech recognition with cochlear implants Audiol Neurootol. 2005 May-Jun; 10(3):169-84. . View in PubMed

Interactions between cochlear implant electrode insertion depth and frequency-place mapping J Acoust Soc Am. 2005 Mar; 117(3 Pt 1):1405-16. . View in PubMed

Speech and music have different requirements for spectral resolution Int Rev Neurobiol. 2005; 70:121-34. . View in PubMed

Frequency-place compression and expansion in cochlear implant listeners J Acoust Soc Am. 2004 Nov; 116(5):3130-40. . View in PubMed

The number of spectral channels required for speech recognition depends on the difficulty of the listening situation Acta Otolaryngol Suppl. 2004 May; (552):50-4. . View in PubMed

The multichannel auditory brainstem implant: how many electrodes make sense? J Neurosurg. 2004 Jan; 100(1):16-23.. View in PubMed

Speech recognition under conditions of frequency-place compression and expansion J Acoust Soc Am. 2003 Apr; 113(4 Pt 1):2064-76. . View in PubMed

Use of a multichannel auditory brainstem implant for neurofibromatosis type 2 Stereotact Funct Neurosurg. 2003; 81(1-4):110-4. . View in PubMed

The relative importance of amplitude, temporal, and spectral cues for cochlear implant processor design Am J Audiol. 2002 Dec; 11(2):124-7. . View in PubMed

Perceptual learning following changes in the frequency-to-electrode assignment with the Nucleus-22 cochlear implant J Acoust Soc Am. 2002 Oct; 112(4):1664-74. . View in PubMed

Frequency mapping in cochlear implants Ear Hear. 2002 Aug; 23(4):339-48. . View in PubMed

Holes in hearing J Assoc Res Otolaryngol. 2002 Jun; 3(2):185-99. . View in PubMed

Multichannel auditory brainstem implant: update on performance in 61 patients J Neurosurg. 2002 Jun; 96(6):1063-71. . View in PubMed

Speech dynamic range and its effect on cochlear implant performance J Acoust Soc Am. 2002 Jan; 111(1 Pt 1):377-86. . View in PubMed

Speech recognition in noise as a function of the number of spectral channels: comparison of acoustic hearing and cochlear implants J Acoust Soc Am. 2001 Aug; 110(2):1150-63. . View in PubMed

Effects of electrode location on speech recognition with the Nucleus-22 cochlear implant J Am Acad Audiol. 2000 Sep; 11(8):418-28. . View in PubMed

Effects of dynamic range and amplitude mapping on phoneme recognition in Nucleus-22 cochlear implant users Ear Hear. 2000 Jun; 21(3):227-35. . View in PubMed

Speech recognition with reduced spectral cues as a function of age J Acoust Soc Am. 2000 May; 107(5 Pt 1):2704-10. . View in PubMed

Effects of phase duration and electrode separation on loudness growth in cochlear implant listeners J Acoust Soc Am. 2000 Mar; 107(3):1637-44. . View in PubMed

Effect of stimulation rate on phoneme recognition by nucleus-22 cochlear implant listeners J Acoust Soc Am. 2000 Jan; 107(1):589-97. . View in PubMed

Effect of acoustic dynamic range on phoneme recognition in quiet and noise by cochlear implant users J Acoust Soc Am. 1999 Dec; 106(6):L65-70. . View in PubMed

Consonant recordings for speech testing J Acoust Soc Am. 1999 Dec; 106(6):L71-4. . View in PubMed

The effect of frequency allocation on phoneme recognition with the nucleus 22 cochlear implant Am J Otol. 1999 Nov; 20(6):729-34. . View in PubMed

Effects of electrode location and spacing on phoneme recognition with the Nucleus-22 cochlear implant Ear Hear. 1999 Aug; 20(4):321-31. . View in PubMed

Phoneme recognition by cochlear implant users as a function of signal-to-noise ratio and nonlinear amplitude mapping J Acoust Soc Am. 1999 Aug; 106(2):L18-23. . View in PubMed

Effects of electrode configuration and frequency allocation on vowel recognition with the Nucleus-22 cochlear implant Ear Hear. 1999 Aug; 20(4):332-44. . View in PubMed

Psychophysical laws revealed by electric hearing Neuroreport. 1999 Jun 23; 10(9):1931-5. . View in PubMed

Recognition of spectrally degraded and frequency-shifted vowels in acoustic and electric hearing J Acoust Soc Am. 1999 Mar; 105(3):1889-900. . View in PubMed

Effects of noise and spectral resolution on vowel and consonant recognition: acoustic and electric hearing J Acoust Soc Am. 1998 Dec; 104(6):3586-96. . View in PubMed

Effects of amplitude nonlinearity on phoneme recognition by cochlear implant users and normal-hearing listeners J Acoust Soc Am. 1998 Nov; 104(5):2570-7. . View in PubMed

Gap detection as a measure of electrode interaction in cochlear implants J Acoust Soc Am. 1998 Oct; 104(4):2372-84. . View in PubMed

Speech recognition with altered spectral distribution of envelope cues J Acoust Soc Am. 1998 Oct; 104(4):2467-76. . View in PubMed

Importance of tonal envelope cues in Chinese speech recognition J Acoust Soc Am. 1998 Jul; 104(1):505-10. . View in PubMed

Forward masked excitation patterns in multielectrode electrical stimulation J Acoust Soc Am. 1998 May; 103(5 Pt 1):2565-72. . View in PubMed

Within-channel gap detection using dissimilar markers in cochlear implant listeners J Acoust Soc Am. 1998 May; 103(5 Pt 1):2515-9. . View in PubMed

Design for an inexpensive but effective cochlear implant Otolaryngol Head Neck Surg. 1998 Feb; 118(2):235-41. . View in PubMed

Speech recognition as a function of the number of electrodes used in the SPEAK cochlear implant speech processor J Speech Lang Hear Res. 1997 Oct; 40(5):1201-15. . View in PubMed

Multi-unit mapping of acoustic stimuli in gerbil inferior colliculus Hear Res. 1997 Jun; 108(1-2):145-56. . View in PubMed

Threshold-distance measures from electrical stimulation of human brainstem IEEE Trans Rehabil Eng. 1997 Mar; 5(1):70-4. . View in PubMed

Place pitch discrimination and speech recognition in cochlear implant users S Afr J Commun Disord. 1996; 43:27-40. . View in PubMed

Loudness of simple and complex stimuli in electric hearing Ann Otol Rhinol Laryngol Suppl. 1995 Sep; 166:235-8. . View in PubMed

Possible origins of the non-monotonic intensity discrimination function in forward masking Hear Res. 1995 Feb; 82(2):216-24. . View in PubMed

Loudness-coding mechanisms inferred from electric stimulation of the human auditory system Science. 1994 Apr 22; 264(5158):564-6. . View in PubMed

Auditory brainstem implant: IIPostsurgical issues and performance. Otolaryngol Head Neck Surg. 1993 Jun; 108(6):634-42. . View in PubMed

Auditory brainstem implant: IIssues in surgical implantation. Otolaryngol Head Neck Surg. 1993 Jun; 108(6):624-33. . View in PubMed

Quantitative comparison of electrically and acoustically evoked auditory perception: implications for the location of perceptual mechanisms Prog Brain Res. 1993; 97:261-9. . View in PubMed

Loudness balance between electric and acoustic stimulation Hear Res. 1992 Jul; 60(2):231-5. . View in PubMed

Temporal modulation transfer functions in patients with cochlear implants J Acoust Soc Am. 1992 Apr; 91(4 Pt 1):2156-64. . View in PubMed

Psychophysical measures from electrical stimulation of the human cochlear nucleus Hear Res. 1990 Aug 01; 47(1-2):159-68. . View in PubMed

Forward masking in patients with cochlear implants J Acoust Soc Am. 1990 Aug; 88(2):741-4. . View in PubMed

A computer interface for psychophysical and speech research with the Nucleus cochlear implant J Acoust Soc Am. 1990 Feb; 87(2):905-7. . View in PubMed

Recent advances in cochlear implants J Acoust Soc Am. 1990 Jan; 87(1):421-2. . View in PubMed

A model of threshold for pulsatile electrical stimulation of cochlear implants Hear Res. 1989 Jul; 40(3):197-204. . View in PubMed

Threshold functions for electrical stimulation of the human cochlear nucleus Hear Res. 1989 Jun 15; 40(1-2):173-7. . View in PubMed

Detection of gaps in sinusoids and pulse trains by patients with cochlear implants J Acoust Soc Am. 1989 Jun; 85(6):2587-92. . View in PubMed

Psychophysical suppression of selective portions of pulsation threshold patterns Hear Res. 1986; 21(3):257-60. . View in PubMed

Growth of pulsation threshold of a suppressed tone as a function of its level Hear Res. 1986; 21(3):251-5. . View in PubMed

Threshold and loudness functions for pulsatile stimulation of cochlear implants Hear Res. 1985 May; 18(2):135-43. . View in PubMed

Multichannel electrical stimulation of the auditory nerve in manII. Channel interaction. Hear Res. 1983 Oct; 12(1):1-16. . View in PubMed

Multichannel electrical stimulation of the auditory nerve in manI. Basic psychophysics. Hear Res. 1983 Aug; 11(2):157-89. . View in PubMed

Growth of loudness for sinusoidal and pulsatile electrical stimulation Ann Otol Rhinol Laryngol Suppl. 1981 Mar-Apr; 90(2 Pt 3):13-4. . View in PubMed

Psychophysical measurements relating suppression and combination tones J Acoust Soc Am. 1980 Sep; 68(3):825-9. . View in PubMed

Two-tone unmasking and suppression in a forward-masking situation J Acoust Soc Am. 1976 Jun; 59(6):1460-70. . View in PubMed

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