Faculty Directory
Claus-Peter Richter

Professor of Otolaryngology - Head and Neck Surgery

Professor of Biomedical Engineering


Searle Building
320 E Superior
Chicago, IL 60611



Biomedical Engineering

Research Interests

Development of cochlear implants including novel devices based on neural infrared stimulation, use of laser in clinical settings, micromechanics of the cochlea, imaging; Bioengineering; Hearing; Otolaryngology; Physiology

My primary research interests are the development and improvement of cochlear implant electrodes, and the micromechanics of the mammalian cochlea.

The objectives of the current research projects are to investigate the stimulation of (auditory) neurons with optical radiation, to measure the impedances of cochlear structures and possible current paths for the electrically stimulated cochlea. New placements and designs of cochlear implant electrodes are examined. Furthermore, mechanical properties, such as stiffness and mass of cochlear structures are examined in normal and developing animals. Currently a novel technique is developed to visualize soft tissue structures without opening the bony cochlear wall.

Funding is provided by the National Intstitute of Health (NIH) and the E.R. Capita Foundation to study the stimulation of neurons using optical radiation and by the National Science Foundation (NSF) for cochlear micromechanics.

Selected Publications

Articles followed by PubMed IDs.

Optical stimulation of auditory neurons: effects of acute and chronic deafening.
Richter CP, Bayon R, Izzo AD, Otting M, Suh E, Goyal S, Hotaling J, Walsh JT
Hearing research 2008 Aug; 242(1-2):42-51
PMID: 18321670

Laser stimulation of auditory neurons: effect of shorter pulse duration and penetration depth.
Izzo AD, Walsh JT, Ralph H, Webb J, Bendett M, Wells J, Richter CP
Biophysical journal 2008 Apr 15; 94(8):3159-66
PMID: 18192375

Developmental changes of mechanics measured in the gerbil cochlea.
Emadi G, Richter CP
Journal of the Association for Research in Otolaryngology : JARO 2008 Mar; 9(1):22-32
PMID: 18046606

Tectorial membrane stiffness gradients.
Richter CP, Emadi G, Getnick G, Quesnel A, Dallos P
Biophysical journal 2007 Sep 15; 93(6):2265-76
PMID: 17496047

Roles of the Espin Actin-Bundling Proteins in the Morphogenesis and Stabilization of Hair Cell Stereocilia Revealed in CBA/CaJ Congenic Jerker Mice.
Sekerková G, Richter CP, Bartles JR
PLoS genetics 2011 Mar; 7(3):e1002032
PMID: 21455486

Unbiased counting of neurons in the cochlea of developing gerbils.
Richter CP, Kumar G, Webster E, Banas SK, Whitlon DS
Hearing research 2011 Feb 15; :
PMID: 21329751

Acoustic events and ¿optophonic¿ cochlear responses induced by pulsed near infrared LASER.
Teudt I, Maier H, Richter CP, Kral A
IEEE transactions on bio-medical engineering 2011 Jan 28; :
PMID: 21278011

Infrared Photostimulation of the Crista Ampullaris.
Rajguru SM, Richter CP, Matic AI, Holstein G, Highstein SM, Dittami GM, Rabbitt RD
The Journal of physiology 2011 Jan 17; :
PMID: 21242259

Laser stimulation of single auditory nerve fibers.
Littlefield PD, Vujanovic I, Mundi J, Matic AI, Richter CP
The Laryngoscope 2010 Oct; 120(10):2071-82
PMID: 20830761

Optical cochlear implants: evaluation of surgical approach and laser parameters in cats.
Rajguru SM, Matic AI, Robinson AM, Fishman AJ, Moreno LE, Bradley A, Vujanovic I, Breen J, Wells JD, Bendett M, Richter CP
Hearing research 2010 Oct 1; 269(1-2):102-11
PMID: 20603207

CO(2) laser fiber soft cochleostomy: development of a technique using human temporal bones and a guinea pig model.
Fishman AJ, Moreno LE, Rivera A, Richter CP
Lasers in surgery and medicine 2010 Mar; 42(3):245-56
PMID: 20333743

Electrical impedance measurements of cochlear structures using the four-electrode reflection-coefficient technique.
Kumar G, Chokshi M, Richter CP
Hearing research 2010 Jan; 259(1-2):86-94
PMID: 19857561

Imaging of cochlear tissue with a grating interferometer and hard X-rays.
Richter CP, Shintani-Smith S, Fishman A, David C, Robinson I, Rau C
Microscopy research and technique 2009 Dec; 72(12):902-7
PMID: 19455683

The importance of auricular prostheses for speech recognition.
Walsh WE, Dougherty B, Reisberg DJ, Applebaum EL, Shah C, O'Donnell P, Richter CP
Archives of facial plastic surgery : official publication for the American Academy of Facial Plastic and Reconstructive Surgery, Inc. and the International Federation of Facial Plastic Surgery Societies 2008 Sep-Oct; 10(5):321-8
PMID: 18794410

Optical stimulation of the facial nerve: a new monitoring technique?
Teudt IU, Nevel AE, Izzo AD, Walsh JT, Richter CP
The Laryngoscope 2007 Sep; 117(9):1641-7
PMID: 17607145

Otoprotective effects of dexamethasone in the management of pneumococcal meningitis: an animal study.
Kim HH, Addison J, Suh E, Trune DR, Richter CP
The Laryngoscope 2007 Jul; 117(7):1209-15
PMID: 17603319

Optical parameter variability in laser nerve stimulation: a study of pulse duration, repetition rate, and wavelength.
Izzo AD, Walsh JT, Jansen ED, Bendett M, Webb J, Ralph H, Richter CP
IEEE transactions on bio-medical engineering 2007 Jun; 54(6 Pt 1):1108-14
PMID: 17554829

The hemicochlea preparation of the guinea pig and other mammalian cochleae.
Teudt IU, Richter CP
Journal of neuroscience methods 2007 May 15; 162(1-2):187-97
PMID: 17327136

Selectivity of neural stimulation in the auditory system: a comparison of optic and electric stimuli.
Izzo AD, Suh E, Pathria J, Walsh JT, Whitlon DS, Richter CP
Journal of biomedical optics 2007 Mar-Apr; 12(2):021008
PMID: 17477715

Tissue resistivities determine the current flow in the cochlea.
Micco AG, Richter CP
Current opinion in otolaryngology & head and neck surgery 2006 Oct; 14(5):352-5
PMID: 16974151

Laser stimulation of the auditory nerve.
Izzo AD, Richter CP, Jansen ED, Walsh JT
Lasers in surgery and medicine 2006 Sep; 38(8):745-53
PMID: 16871623

Electrical resistivity measurements in the mammalian cochlea after neural degeneration.
Micco AG, Richter CP
The Laryngoscope 2006 Aug; 116(8):1334-41
PMID: 16885732

Visualizing soft tissue in the mammalian cochlea with coherent hard X-rays.
Rau C, Robinson IK, Richter CP
Microscopy research and technique 2006 Aug; 69(8):660-5
PMID: 16788978

Cochlear preservation after meningitis: an animal model confirmation of adjunctive steroid therapy.
Addison J, Kim HH, Richter CP
The Laryngoscope 2006 Feb; 116(2):279-82
PMID: 16467719

Survival and morphology of auditory neurons in dissociated cultures of newborn mouse spiral ganglion.
Whitlon DS, Ketels KV, Coulson MT, Williams T, Grover M, Edpao W, Richter CP
Neuroscience 2006; 138(2):653-62
PMID: 16413120

Modifying cochlear implant design: advantages of placing a return electrode in the modiolus.
Ho SY, Wiet RJ, Richter CP
Otology & neurotology : official publication of the American Otological Society, American Neurotology Society [and] European Academy of Otology and Neurotology 2004 Jul; 25(4):497-503
PMID: 15241228

Stiffness of the gerbil basilar membrane: radial and longitudinal variations.
Emadi G, Richter CP, Dallos P
Journal of neurophysiology 2004 Jan; 91(1):474-88
PMID: 14523077

Motion analysis in the hemicochlea.
Cai H, Richter CP, Chadwick RS
Biophysical journal 2003 Sep; 85(3):1929-37
PMID: 12944305

Prestin expression in the cochlea of the reeler mouse.
Zheng J, Richter CP, Cheatham MA
Neuroscience letters 2003 Aug 14; 347(1):13-6
PMID: 12865130

High-frequency sensitivity of the mature gerbil cochlea and its development.
Overstreet EH, Richter CP, Temchin AN, Cheatham MA, Ruggero MA
Audiology & neuro-otology 2003 Jan-Feb; 8(1):19-27
PMID: 12566689

Cochlear dimensions obtained in hemicochleae of four different strains of mice: CBA/CaJ, 129/CD1, 129/SvEv and C57BL/6J.
Keiler S, Richter CP
Hearing research 2001 Dec; 162(1-2):91-104
PMID: 11707356

A reconsideration of sound calibration in the mouse.
Pearce M, Richter CP, Cheatham MA
Journal of neuroscience methods 2001 Mar 30; 106(1):57-67
PMID: 11248341

Use of the pinna reflex as a test of hearing in mutant mice.
Cheatham MA, Pearce M, Richter CP, Onodera K, Shavit JA
Audiology & neuro-otology 2001 Mar-Apr; 6(2):79-86
PMID: 11385181

Development of the gerbil inner ear observed in the hemicochlea.
Richter CP, Edge R, He DZ, Dallos P
Journal of the Association for Research in Otolaryngology : JARO 2000 Nov; 1(3):195-210
PMID: 11545226

Sodium, potassium, chloride and calcium concentrations measured in pigeon perilymph and endolymph.
Sauer G, Richter CP, Klinke R
Hearing research 1999 Mar; 129(1-2):1-6
PMID: 10190746

Morphology of the unfixed cochlea.
Edge RM, Evans BN, Pearce M, Richter CP, Hu X, Dallos P
Hearing research 1998 Oct; 124(1-2):1-16
PMID: 9822898

Basilar membrane vibration in the gerbil hemicochlea.
Richter CP, Evans BN, Edge R, Dallos P
Journal of neurophysiology 1998 May; 79(5):2255-64
PMID: 9582202

Modeling stochastic spike train responses of neurons: an extended Wiener series analysis of pigeon auditory nerve fibers.
Joeken S, Schwegler H, Richter CP
Biological cybernetics 1997 Feb; 76(2):153-62
PMID: 9116078

Development of activity patterns in auditory nerve fibres of pigeons.
Richter CP, Sauer G, Hoidis S, Klinke R
Hearing research 1996 May; 95(1-2):77-86
PMID: 8793510

Rate-intensity-functions of pigeon auditory primary afferents.
Richter CP, Heynert S, Klinke R
Hearing research 1995 Mar; 83(1-2):19-25
PMID: 7607985

Preferred intervals in birds and mammals: a filter response to noise?
Klinke R, Müller M, Richter CP, Smolders J
Hearing research 1994 Apr; 74(1-2):238-46
PMID: 8040094

Effects of endolymphatic and perilymphatic application of salicylate in the pigeon. I: Single fiber activity and cochlear potentials.
Shehata-Dieler WE, Richter CP, Dieler R, Klinke R
Hearing research 1994 Apr; 74(1-2):77-84
PMID: 8040101

Effects of endolymphatic and perilymphatic application of salicylate in the pigeon. II: Fine structure of auditory hair cells.
Dieler R, Shehata-Dieler WE, Richter CP, Klinke R
Hearing research 1994 Apr; 74(1-2):85-98
PMID: 8040102

Artifact-free application of drugs into the avian endolymphatic space.
Richter CP, Klinke R
Journal of neuroscience methods 1994 Mar; 51(2):171-5
PMID: 8051948