Eric Hunter, MS, PhD
 Eric
J. Hunter is a research scientist for the National Center for
Voice and Speech at The Denver Center for the Performing Arts in
Dever, CO. Dr. Hunter completed his training in the area of speech
science under the direction of Dr. Ingo Titze via the National Research
Service Award traineeship and received his doctorate from the Department
of Speech Pathology and Audiology at the University of Iowa; his
dissertation topic used continuum mechanics to model vocal fold
posturing. Originally from a small farming community in southern
Idaho, Dr. Hunter earned bachelor's and master's degrees from Brigham
Young University in physics and mathematics with an emphasis in
acoustics and vibration. His master's thesis, which focused on designing
and testing visual aides for the deaf, http://www.geocities.com/ericsresearch/TriDesign.html,
shifted his interest from musical acoustics to speech acoustics.
Dr. Hunter is on the board of editors of the International Journal
of Research in Choral Singing and a member of the American Society
of Biomechanics and the Acoustical Society of America. Currently
he is the Principle Investigator for an NIH/NIDCD grant entitled,
"A Computational Tool for Simulation of Phonosurgical Procedures").
He is married to Laura Hunter and has three children.
RESEARCH INTERESTS:
Research interests include signal processing, biomechanics of speech
articulators (specifically the larynx and laryngeal muscle mechanics),
vibrational and posturing models of the vocal system, muscle mechanics
and muscle models, and biomechanical properties of tissues. Broader
academic interests include: recording techniques, speech perception,
musical acoustics, integrated circuit processes creation, modeling
integrated circuits, and machine recognition of speech.
Mailing Address:
The Denver Center for the Performing Arts
National Center for Voice and Speech
1101 13th Street
Denver, CO 80204
phone: 303-446-4839
fax: 303-893-6487
GRANTS:
R03 DC006801 A Computational Tool for Simulation
of Phonosurgical Procedures [http://www.ncvs.org/ncvs/groups/SPP/index.html]
EDUCATION:
2001 University of Iowa PhD, Speech & Hearing
Science
1997 Brigham Young University MS, Physics
1995 Brigham Young University BS, Physics (major), Mathematics (minor)
EXPERIENCE:
| 2004- |
Editorial Board International Journal of Research
in Choral Singing [www.choralresearch.org]
“The International Journal of Research in Choral Singing
is a publication of the Consortium for Choral Research, an international
research interest group comprised of scholars who are both established
researchers and active choral musicians.” |
| 2003- |
Asst Research Scientist National Center for
Voice & Speech, DCPA
PI of A Computational Tool for Simulation of Phonosurgical Procedures
(NIDCD R03 DC006801) [http://www.ncvs.org/ncvs/groups/SPP/index.html]
Investigator and Team Leader of Research toward Occupational
Safety in Vocalization (NIDCD R01 DC04436) including the supervision
and coordination of team members for data collection and analysis.
[http://www.ncvs.org/ncvs/groups/occupational/index.html]
|
|
2003- |
Summer Vocology Institute instructor; National Center for Voice
and Speech at The Denver Center for the Performing Arts (course:
Instrumentation for Voice Analysis) |
|
2005- |
Lecturer in Department of Physics, University of Colorado at
Denver (course: Physics of Music and Sound) |
| 2001-2003 |
Asst Research Scientist National Center for
Voice & Speech, UofI
Researcher on Neuromuscular Control of the Larynx in Phonation
(NIDCD R01 DC04347) |
| 1999-2001 |
Lecturer, Acoustics Dept of Speech Path &
Audiology, UofI
Instructor (2 TAs), Basic Acoustics for Speech and Hearing |
| 1997-2001 |
Trainee National Center for Voice & Speech,
UofI
National Center for Voice and Speech (NIH P60 DC00976), |
| 1997-2001 |
PhD Candidate Dept of Speech Path & Audiology,
UofI |
PROFESSIONAL MEMBERSHIPS
Acoustical Society of America [http://asa.aip.org/]
American Society of Biomechanics [http://asb-biomech.org/]
AWARDS/FELLOWSHIPS
2001 National Research Service Award Doctoral Fellow,
Univ. of Iowa
1995 BYU Office of Research & Creative Work Recognition Award,
BYU
REFEREED/PEER-REVIEWED PUBLICATIONS:
Hunter, E.J., and Titze, I.R., (In Press) Refinements in Modeling
the Passive Properties of Laryngeal Soft Tissue. Journal of Applied
Physiology.
Hunter, E.J., Svec, J.G., and Titze,
I.R. (In Press) Comparison of the Produced and Perceived Voice Range
Profiles In Untrained And Trained Classical Singers. J.Voice
Hunter, E.J., Alipour, F., and Titze, I.R., (2006) Sensitivity of
Elastic Properties to Measurement Uncertainties in Laryngeal Muscles
with Implications for Voice Fundamental Frequency Prediction. J
Voice. 20(4):513-26.
Titze, I.R., Hunter, E.J., and Svec, J.G. (2007) Voicing and Silence
Periods in Daily and Weekly Vocalizations of Teachers. J. Acoust.
Soc. Am. 121(1):469-78.
Hunter, E.J. and Titze, I.R. A Technical Report. Individual Subject
Laryngeal Dimensions of Multiple Mammalian Species for Biomechanical
Models. Ann.Otol.Rhinol.Laryngol. 2005. (In Press)
Hunter, E.J. and Titze, I.R. Review of range of arytenoid cartilage
motion. Acoustic Research Letters Online, 6(3), 112-117, 2005.
Hunter, E.J. and Titze, I.R. Overlap of Hearing and Voicing Ranges in
Singing. Journal of Singing, 61 (4):387-392, 2004.
Alipour, F., Titze, I.R., E. J. Hunter, and N Tayama. Active and Passive
Properties of Canine Abduction/Adduction Laryngeal Muscles. J.Voice. (19(3), 350-359)
Titze, I.R. and Hunter, E.J. (2004). Normal Vibration Frequencies of
the Vocal Ligament. J. Acoust. Soc. Am. 115(5), 2264-2269.
Hunter, E.J., Titze, I.R., and Alipour, F. (2004). A three-dimensional
model of vocal fold adduction/abduction. J. Acoust. Soc. Am. 115(4),
1747-1759.
Kim, M.J., Hunter, E.J., and Titze, I.R. (2004). Comparison of Human,
Canine, and Ovine Laryngeal Dimensions. Annals of Otology, Rhinology and
Laryngology. 113(1), 60-68.
Titze, I.R., Bergan, C.C., Hunter, E.J., and Story, B. (2003). Source
and Filter Adjustments Governing the Perception of the Vocal Qualities
Twang and Yawn. Logopedics, Phoniatrics, and Vocology, 28(4), 147-155.
CONFERENCE PROCEEDINGS:
| VUP Paper (this section is in revision) |
| Ingo R. Titze; Eric J. Hunter; and Jan G. Švec |
| |
In classrooms, teachers need to speak frequently, and often
loudly, risking occupational damage to their voices. How
much do teachers actually speak in the course of a school
day? Ingo Titze and Eric Hunter (ehunter@dcpa.org) of the
National Center for Voice and Speech (Denver Center for the
Performing Arts and also the University of Iowa) will
present some detailed new results from a National Center for
Voice and Speech data bank (nearly 6600 hrs of voice data).
The project tracked 31 teachers over two weeks and recorded
their voices during all waking hours. The data captured
voice-production events as short as 0.0316 seconds and as
long as 100 s. On average, the teachers had 1,800
occurrences of voicing per hour at work, compared to 1,200
per hour during non-work periods (as many as 20,000 per
day). Voicing occurred 23% of the total time at work and
diminished to 13% during off-work hours and 12% on weekends.
According to Titze and Hunter, the study helps pave the way
for understanding vocal fatigue in terms of repetitive
motion (voice on/off) and collision (vibration) of tissue,
as well as how the voice can recover from physical stress |
| |
| Titze, I.R., and Hunter, E.J. (2004).
“Normal vibration frequencies of the vocal ligament.”
American Society of Biomechanics Annual Meeting 2004, September
8-11, 2004, Portland, Oregon. [http://www.biomechresearch.org/home.html] |
| Hunter, E.J., and Titze, I.R. (2004).
“A three-dimensional model of vocal fold abduction/adduction.”
American Society of Biomechanics Annual Meeting 2004, September
8-11, 2004, Portland, Oregon. [http://www.biomechresearch.org/home.html] |
| Hunter, E.J., and Titze, I.R. (2004).
“Overlap of hearing and voicing ranges in singing.”
2nd International Physiology and Acoustics of Singing Conference,
NCVS at Denver, October 7-9, 2004 [http://www.ncvs.org/pas/2004] |
| Alipour, F., Hunter, E.J., and
Titze, I.R. (2003). “Viscoelastic properties of laryngeal
posturing muscles.” J. Acoust. Soc. Am. 114, 2458 (2003).
|
| |
Viscoelastic properties of
canine laryngeal muscles were measured in a series of in vitro
experiments. Laryngeal posturing that controls vocal fold
length and adduction/abduction is an essential component of
the voice production. The dynamics of posturing depends on
the viscoelastic and physiological properties of the laryngeal
muscles. The time-dependent and nonlinear behaviors of these
tissues are also crucial in the voice production and pitch
control theories. The lack of information on some of these
muscles such as posterior cricoarytenoid muscle (PCA), lateral
cricoarytenoid muscle (LCA), and intraarytenoid muscle (IA)
was the major incentive for this study. Samples of PCA and
LCA muscles were made from canine larynges and mounted on
a dual-servo system (Ergometer) as described in our previous
works. Two sets of experiments were conducted on each muscle,
a 1-Hz stretch and release experiment that provides stress–strain
data and a stress relaxation test. Data from these muscles
were fitted to viscoelastic models and Young's modulus and
viscoelastic constants are obtained for each muscle. Preliminary
data indicates that elastics properties of these muscles are
similar to those of thyroarytenoid and cricothyroid muscles.
The relaxation response of these muscles also shows some similarity
to other laryngeal muscles in terms of time constants. |
| Kim, M.J., Hunter, E.J., Titze,
I.R. “Comparison of human, canine, and ovine laryngeal
dimensions.” J. Acoust. Soc. Am. 114, 2397 (2003). |
| |
Geometric measurement on the laryngeal skeleton
is a fundamental step in laryngeal studies, especially in biomechanical
modeling. Traditionally, canine larynges have been used as models
of the human larynx because of their similarity in size and
gross structure, but the search continues for an alternative
model because of the diminishing availability of the canine
species for research in the U.S. In this study, a revised methodology
for defining and labeling laryngeal framework parameters was
proposed. Ovine laryngeal cartilages were measured and compared
to those of human and canine cartilages previously reported
in the literature. The ovine cricoid, thyroid and arytenoids
cartilages were significantly different from the human and canine.
Also, the lack of a definite border between the true and false
vocal folds revealed that the ovine model may not always be
suitable for a direct comparison to the human larynx in phonation. |
Hunter, E.J.,
and Titze, I.R. “Comparison of hearing and voicing ranges
in singing.” J. Acoust. Soc. Am. 113, 2243 (2003).
|
| |
The spectral and dynamic ranges of the human
voice of professional and nonprofessional vocalists were compared
to the auditory hearing and feeling thresholds at a distance
of one meter. In order to compare these, an analysis was done
in true dB SPL, not just relative dB as is usually done in
speech analysis. The methodology of converting the recorded
acoustic signal to absolute pressure units was described.
The human voice range of a professional vocalist appeared
to match the dynamic range of the auditory system at some
frequencies. In particular, it was demonstrated that professional
vocalists were able to make use of the most sensitive part
of the hearing thresholds (around 4 kHz) through the use of
a learned vocal ring or singer's formant. |
Hunter, E.J. (2002). “Optimization
of Passive Tissue Model Parameters of Intrinsic Laryngeal
Adductory Muscles.” Proceedings of IV World Congress
of Biomechanics, Calgary.
|
Hunter, E.J. (2002). “Three
Dimensional Biomechanical Model of Vocal Fold Posturing.”
Proceedings of 7th International Conference on Spoken Language
Processing, Denver.
|
| Hunter, E.J., Titze, I.R., Alipour,
F. “Finite-element analysis of passive vocal fold posturing
using nonlinear muscle responses.” J. Acoust. Soc. Am.
109, 2413 (2001). |
| |
A finite-element model of the passive properties
of laryngeal muscles was created, based on nonlinear stress–strain
responses of laryngeal muscular tissue [E. J. Hunter and I.
Titze, J. Acoust. Soc. Am. 108, 2531 (2000)]. Using this finite-element
muscle model as a building block, groups of muscles are used
to construct a 3-D tissue model of vocal fold posturing. Vocal
fold configurations were studied with assumed muscle stresses
applied to the adductor–abductor muscles. Results comply,
in the linear region, with earlier results on a 2-D linear model
that had constant thickness [E. J. Hunter, J. Acoust. Soc. Am.
106, 2540 (1999)], but now take into account more accurately
the high strains |
| Hunter, E.J.,
and Titze, I.R. (2000). “Parameters for a first-order
Kelvin model of laryngeal muscles.” J. Acoust. Soc. Am.
108, 2531 (2000). |
| |
Because the intrinsic muscles of the larynx
determine vocal fold posturing in phonation, a model of vocal
fold posturing requires data from the passive and active viscoelastic
properties of these intrinsic muscles. Using reported one-dimensional
active (twitch and tetanus) and passive muscle (step elongation
and relaxation) measures from fresh excised canine laryngeal
muscles, one-dimensional first-order Kelvin model parameters
were obtained. Obtaining these parameters was accomplished
through optimization, where force-elongation patterns predicted
by the model were compared to measured muscular passive cyclic
force-elongation patterns. These parameters are reported along
with the design for the Kelvin model. The results of this
study, which will be integrated into a larger finite-element
posturing model, become the first step in predicting the vocal
fold configurations needed for phonation. |
| Hunter, E.J. “Finite element
analysis of vocal fold posturing.” J. Acoust. Soc. Am.
106, 2240 (1999) |
| Hunter, E.J., and Strong, W.J.
“Geometrical display of speech spectra as an aid to lipreading.”
J. Acoust. Soc. Am. 102, 3166 (1997). |
| |
A geometrical display of speech spectra intended
as an adjunct to lipreading was developed. Spectra were calculated
at 5-ms intervals from speech sound pairs ambiguous to lipreaders.
The spectra were displayed as sequences of irregular decagons.
Human subjects were asked to discriminate between pairs of spectral
decagon sequences derived from pairs of ambiguous speech sounds.
Subjects were able to discriminate between most of the visual
spectral patterns derived from ambiguous sounds. However, spectral
patterns associated with the voiced/unvoiced contrast in some
stop pairs were not discriminated consistently. |
INVITED LECTURES AND CONFERENCE PRESENTATIONS:
| 2001 |
Invited Pedagogy Class Lecturer Univ. of N.
Iowa, Cedar Falls, IA
“Anatomy of the Larynx and How to Optimize Its Use for
Vocal Performance.” |
| 1999 |
Guest Speaker Rotary Club of Manchester, Manchester
IA
“What is the NCVS?” and “Caring for Your Voice”
|
| 1998 |
Speaker NCVS Meeting, Madison WI Madison, Wisconsin
“Controlling Computer Models of Speech in Real Time Using
a MIDI Keyboard” |
|
