OUR PEOPLE

Dan Mennitt

Ph.D., P.E.

Mechanical Engineering

Managing Engineer

Denver

Office: +1-303-802-3428

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Academic Credentials

Ph.D., Magna Cum Laude, Mechanical Engineering, Virginia Polytechnic Institute and State University, 2008
B.S., Magna Cum Laude, Mechanical Engineering, Virginia Polytechnic Institute and State University, 2004

Licenses & Certifications

Professional Engineer, Colorado, #PE.0058367
Professional Engineer, Wisconsin, #48642-6
Certified Occupational Hearing Conservationist

Academic Appointments

Research Scientist III, Department of Electrical and Computer Engineering, Colorado State University, 2018-2019
Research Scientist II, Department of Electrical and Computer Engineering, Colorado State University, 2015-2018
Research Scientist I, Department of Electrical and Computer Engineering, Colorado State University, 2010-2015
Graduate Research Assistant, Department of Mechanical Engineering, Virginia Polytechnic Institute and State University, 2004-2008

Professional Honors

The Robert Bradford Newman Medal for Merit in Architectural Acoustics, 2005
Best Paper By A Young Presenter, 153rd Meeting of the Acoustical Society of America, 2007.

Professional Affiliations

Acoustical Society of America
Institute of Noise Control Engineering
Technical Committees
American Society for Testing and Materials: ASTM Committee E33 on Building and Environmental Acoustics

Dr. Mennitt specializes in acoustics and is skilled in the characterization, design, and modeling of acoustical environments and devices. His primary areas of expertise include noise and vibration control, environmental noise, and audio engineering.

Dr. Mennitt has applied his expertise to noise and vibration control of machines, buildings, medical devices, consumer products, and other equipment. His experience includes applications involving mechanical waves in fluids and solids in the sonic and ultrasonic range. He routinely performs testing to characterize acoustical quantities such as sound power, directivity, transmissibility, and frequency response. Dr. Mennitt also draws on analytical and numerical methods to evaluate the mechanisms of sound generation, dominant sources, and transmission paths of various systems and components. He has developed and implemented solutions to effectively isolate vibration, reduce noise transmission to sensitive areas, and support the development of quiet products.

Dr. Mennitt's work is rooted in the human response to sound and vibration. His project work has involved the acquisition and the analysis of data to estimate perception, audibility, loudness, annoyance, sound quality, and other psychoacoustic metrics. Dr. Mennitt is a certified Occupational Hearing Conservationist and has evaluated occupational noise exposure, hearing conservation programs, and the efficacy of mitigative measures to protect hearing in the workplace and other settings.

Dr. Mennitt has worked extensively with federal agencies to assess environmental noise and the consequences of noise exposure to humans and ecological systems. Prior to joining Exponent, he worked in partnership with Colorado State University and the National Park Service's Natural Sounds and Night Skies Division to manage acoustical environments. His research involved the spatiotemporal patterns of environmental sound on landscape scales, impacts of noise exposure, acoustical transducers, bioacoustics, flow noise, and predictive modeling. Dr. Mennitt has designed acoustical devices and methods for data acquisition, calibration, and monitoring sound in extremely quiet environments. While at Colorado State University, Dr. Mennitt also taught a course on acoustics, noise, and signal processing.

Dr. Mennitt's experience in computational acoustics includes deterministic time and frequency domain simulations of acoustic propagation as well as applications that exploit statistical learning and predictive modeling. He led a multidisciplinary team to pioneer technology that uses geospatial data to generate comprehensive maps of environmental sound levels and noise exposure on continental scales. He has worked with academia, government, and industry to translate these estimates to implications for land management, ecological, epidemiological, military, and commercial applications.

Dr. Mennitt's background is in mechanical engineering. He performed his doctoral work at Virginia Tech's Vibration and Acoustics Laboratory, developing terrestrial sonar systems for localization and tracking of acoustic sources in free-field and cluttered environments. During this research, he developed robust statistical methods for classification of acoustical signals and fusion of information from distributed sensor networks. He has also created tools for beamforming, adaptive filtering, speech processing, and other signal processing applications with free field and diffracting microphone arrays. While at the Vibration and Acoustics Laboratory, he conducted testing with anechoic and reverberation rooms, intensity probes, impedance tubes, modal impact hammers, accelerometers, and shakers. Other graduate work included applications in spatial audio, active noise control for signal enhancement, architectural acoustics, music production, and audio engineering. His training and expertise in audio engineering helps Dr. Mennitt conduct educated and critical observations to address acoustical issues.

Noise and Vibration Control Engineering
- Conducted acoustical measurements to characterize the sound power and directivity of an electrical device.
- Evaluated occupational noise exposure, hearing conservation programs, and the efficacy of mitigative measures to protect employee hearing.
- Prescribed and evaluated acoustical enclosures and treatments to provide sufficient noise reduction within design constraints.
- Investigated a flow induced resonance in a steam pipeline and designed noise controls to reduce structural vibration.
- Measured and analyzed meteorological, sound, and vibration data to determine the root cause of wind-induced sound and vibration of a transmission line and develop noise controls.
- Evaluated the potential effects of vibration on people and sensitive instruments in buildings and vehicles.
- Designed experiments and conducted path analyses to determine the root cause of noise and vibration transmission in a residential apartment building.
- Conducted follow-up analyses and recommended solutions to effectively isolate vibration and reduce noise transmission to sensitive areas and receivers.
- Hydrophone measurement of ultrasonic emissions in water to determine compliance with regulatory guidance.
- Applied analytical models of sound emission characteristics to inform test methods for an airborne ultrasonic acoustic source.
- Determined the mechanisms of sound generation in a micro-electromechanical system using analytical calculations and numerical models.
- Designed a constrained layer damping treatment to attenuate structureborne noise in an acoustical enclosure.
- Identified the dominant sources and transmission paths of noise in a medical device using analytical calculations and experimental sound and vibration data.
- Measured the dynamics of a lightweight structure in a consumer product using laser doppler vibrometry to solve problems related to fatigue and NVH (noise, vibration, and harshness).
Environmental Noise
- Conducted environmental noise assessments of industrial facilities, construction activity, utilities, and transportation projects to assess the potential for environmental impacts.
- Designed, executed, and analyzed acoustic field surveys of existing ambient conditions in buildings, urban communities, and remote areas.
- Modeled acoustic propagation from noise sources to estimate the potential impacts to local communities and determine compliance with regulations.
- Developed and recommended noise control strategies for projects in which mitigative measures were warranted.
- Conducted field measurements of airborne and ground-borne noise and vibration arising from rail systems to evaluate human exposure and response in buildings.
- Evaluated models and conducted field measurements to assess highway noise abatement strategies and the transmission loss of building facades.
Audio Engineering and Perception
- Assessed the active noise cancelling performance of headphones and passive noise reduction performance of hearing protection devices in the laboratory using industry accepted procedures and standards.
- Recreated and measured acoustic events to evaluate their subjective perception using psychoacoustic metrics such as time-varying loudness.
- Analyzed sound and vibration data and the characteristics of sources and environments to assess human responses such as perception, audibility, annoyance, and sound quality.
- Devised screening criteria for quieter products based on acoustical metrics and spectral data.
- Analyzed the sound fields of automobile cabins to evaluate the auditory perception of the driver.
- Reviewed patents for musical instruments in support of intellectual property disputes.
- Developed digital filters and signal processing algorithms to analyze data characteristics, detect signals, and enhance audio signals such as speech.
- Evaluated the audibility of sound sources such as alarms and vehicles under various environmental conditions.
Nondestructive Testing and Failure Analysis
- Developed protocols and instrumentation to assess the effect of vibration on nondestructive evaluation of gas pipelines that account for vibroacoustic interaction of shell and fluid dynamics.
- Analyzed measurement data to assess piping vibration sources and the risk of vibration induced fatigue failure in gas pipelines.
- Instrumented turbomachinery and analyzed condition monitoring data to identify component failure and determine maintenance requirements.
- Conducted experimental modal analysis of vibrating structures to determine root cause of failure in conjunction with finite element analyses.
- Conducted failure analysis of a piezoelectric transducer and enclosure.
- Assessed HVAC noise controls in commercial buildings to resolve deficiencies and mitigate occupant annoyance.
M. Senzaki, J. R. Barber, J. N. Phillips, N. H. Carter, C. B. Cooper, M. A. Ditmer, K. M. Fristrup, C. McClure, D. J. Mennitt, L. P. Tyrrell, J. Vukomanovic, A. A. Wilson and C. D. Francis, "Sensory pollutants alter bird phenology and fitness across a continent," Nature 587 (2020):605-609.
D. Paksarian, K. E. Rudolph, E. K. Stapp, G. P. Dunster, J. He, D. J. Mennitt, and K. Merikangas, "Association of Outdoor Artificial Light at Night With Mental Disorders and Sleep Patterns Among US Adolescents," JAMA Psychiatry 77 (2020):1266-1275.
DM Dominoni et. al., "Why conservation biology can benefit from sensory ecology," Nature Ecology & Evolution, 4 (2020): 502-511.
R. T. Buxton, M.F. McKenna, D. J. Mennitt, E. Brown, K. Fristrup, K.R. Crooks, L. M. Angeloni, G. Wittemyer, "Anthropogenic noise in US national parks - sources and spatial extent," Frontiers in Ecology and the Environment 17 (2020): 559-564.
D. J. Mennitt, "An adaptive coupler for the calibration of the arbitrarily shaped microphones," Applied Acoustics 154 (2019):114-120.
K.E. Rudolph, A. Shev, D. Paksarian, K.R. Merikangas, D.J. Mennitt, P. James, and J. A. Casey, "Environmental noise and sleep and mental health outcomes in a nationally representative sample of urban US adolescents," Environmental Epidemiology, 3 (2019): e056.
D. J. Mennitt, K. Fristrup, and B. Notaros, "Characterization of gain and directivity of exponential horn receivers," The Journal of the Acoustical Society of America, 142 (2017):3257-3266.
C. D. Francis, D. Taff, P. Newman, C. White, C. A. Monz, M. Levenhagen, A. R. Petrelli, L. C. Abbott, J. Newton, S. Burson, C. B. Cooper, Kurt M. Fristrup, C. McClure, D. J. Mennitt, M. Giamellaro, J. R. Barber, "Acoustic Environments Matter: Synergistic benefits to humans and ecological communities," Journal of Environmental Management, 203 (2017):245-254.
J. A. Casey, R. Morello-Frosch, D. J. Mennitt, K. M. Fristrup, E. L. Ogburn, and P. James, "Race/Ethnicity, Socioeconomic Status, Residential Segregation, and Spatial Variation in Noise Exposure in the Contiguous United States," Environmental Health Perspectives, 125 (2017):1-10.
R. T. Buxton, M. F. McKenna, D. J. Mennitt, K. M. Fristrup, K. Crooks, L. Angeloni, and G. Wittemyer, "Noise pollution is pervasive in US protected areas." Science 356, no. 6337 (2017):531-533.
D. J. Mennitt and K. Fristrup, "Influential factors and spatiotemporal patterns of environmental sound levels in the contiguous United States," Noise Control Engineering Journal, 64 (2016):342-353.
D. J. Mennitt, K. Fristrup, and K. Sherrill, "A geospatial model of ambient sound pressure levels in the contiguous United States," The Journal of the Acoustical Society of America 135 (2014):2746-2764.
D. J. Mennitt, K.M. Fristrup, "Obtaining calibrated sound pressure levels from consumer digital audio recorders," Applied Acoustics 73 (2012):1138-1145.
K. M. Fristrup, and D. J. Mennitt. "Bioacoustical monitoring in terrestrial environments." Acoustics Today 8(2012):16-24.
D. J. Mennitt, and M. Johnson, "Multiple-array passive acoustic source localization in urban environments," The Journal of the Acoustical Society of America, 127.5 (2010): 2932-2942.
M. Ermann, M. R. F. Kidner, and D. J. Mennitt, "Mapping the sound field of a 400 seat theater," Building Acoustics 13.3 (2006):199-210.
Conference Proceedings
D. J. Mennitt, M. F. McKenna, and K. M. Fristrup, "Continental perspectives of noise exposure and its effects," INTER-NOISE and NOISE-CON Congress and Conference Proceedings, 255 (2017):1168-1172.
D. J. Mennitt and K. Fristrup, "Influential factors and spatiotemporal patterns of environmental sound levels," INTER-NOISE and NOISE-CON Congress and Conference Proceedings, 250 (2015):2029-2040.
D. J. Mennitt, K. Fristrup, K. Sherrill, and L. Nelson, "Mapping sound pressure levels on continental scales using a geospatial sound model," INTER-NOISE and NOISE-CON Congress and Conference Proceedings, 1 (2013):1-11.
D. J. Mennitt, P. Gillett, J. Carneal and M. Johnson, "Tracking Noise Sources Using Multiple Mobile Microphone Arrays," Thirteenth International Congress on Sound and Vibration, Vienna, Austria (2006):1-8.
Technical reports
D. J. Mennitt and B. J. Ikelheimer, "Geospatial sound modeling for military and community noise metrics," Prepared for the United States Army (2017).
Presentations
D.J. Mennitt, D. Joyce, and K. Fristrup, "Benefits and challenges of using consumer audio equipment for unattended acoustical monitoring," The Journal of the Acoustical Society of America, 144, 1828 (2018).
J. A. Casey, A. Shev, D. Paksarian, K. R. Merikangas, D. J. Mennitt, and K. E. Rudolph, "Association between exposure to noise and sleep and mental health outcomes in a nationally-representative sample of U.S. adolescents," 2018 Annual Conference of the International Society for Environmental Epidemiology (2018).
K. Fristrup, M.F. McKenna, and D.J. Mennitt, "Forecasting increases in recreational value that would result from restoration of natural soundscapes in National Parks," The Journal of the Acoustical Society of America, 143, 1806 (2018).
M. F. McKenna, D. J. Mennitt, M. Thompson, J. Stanley, S. Van Parijs, K. M. Fristrup, and L. Hatch, "Including acoustical features in marine ecological prediction," NOAA-Navy Workshop: Soundscape Metrics to Support Marine Protected Area Management, Woods Hole Oceanographic Institution, MA (2018).
D. J. Mennitt, "Classification of wind induced pseudo noise using low resolution features," National Park Service, Natural Resource Stewardship and Science, Fort Collins, CO (2017).
D. J. Mennitt, Megan F. McKenna, and Kurt M. Fristrup, "Continental perspectives of noise exposure and its effects," INTER-NOISE and NOISE-CON Congress and Conference Proceedings, 255 (2017):1168-1172.
D. J. Mennitt and K. Fristrup, "Gain and directivity of exponential horn receivers," The Journal of the Acoustical Society of America 140, 3140 (2016).
D.J. Mennitt and K. Fristrup, "Anomaly detection and other practical considerations for estimating acoustical metrics from time series data," The Journal of the Acoustical Society of America, 140, 3424 (2016).
D. J. Mennitt and K. M. Fristrup, "A geospatial approach to mapping environmental sound levels across the United States," American Society for Photogrammetry and Remote Sensing, Geobytes (2016).
J. A. Casey, R. Morello-Frosch, D. J. Mennitt, K. M. Fristrup, and P. James, "The distribution of noise pollution along racial and socioeconomic lines in the United States," 28th Annual Conference of the International Society of Environmental Epidemiology, Rome, Italy (2016).
P. James, R. Banay, D. J. Mennitt, K. Fristrup, J. Africa, J. Hart, F. Laden, "Noise and Cardiovascular Disease in a Nationwide Cohort Study," 28th Annual Conference of the International Society of Environmental Epidemiology, Rome, Italy (2016).
R. T. Buxton, M. McKenna, E. Brown, D. J. Mennitt, K. Fristrup, K. Crooks, L. Angeloni, G. Wittemyer, "Noise Exposure in U. S. Protected Areas," American Association for the Advancement of Science, Washington DC (2016).
D. J. Mennitt, L. Hatch, K. M. Fristrup, M. Thompson, D. Cholewiak, M. F. McKenna, P. Auster and S. Van Parijs, "A geospatial approach to exploring the soundscape of Stellwagen Bank National Marine Sanctuary," Oceanoise 2015, Vilanova i la Geltrú, Spain (2015).
D. J. Mennitt, E. Brown, and K.M. Fristrup, "Assessing the condition of acoustical resources across the National Park Service Units," 2015 George Wright Society Conference on Parks, Protected Areas, and Cultural Sites, Oakland, CA (2015).
M. F. McKenna, K. M. Fristrup, and D. J. Mennitt, "Predicting historic and current sound levels from point measurements: a geospatial model," Science for Parks, Parks for Science: The Next Century, Berkeley, CA (2015).
K. Fristrup, D. Joyce, E. Lynch, M. Mckenna, D. J. Mennitt, "Monitoring and modeling sound levels at landscape scales in U. S. National Parks," Ecology and acoustics: emergent properties from community to landscape, Paris, France (2014).
D. Risch, P. Auster, D. Cholewiak, K. Fristrup, L. Hatch, M. McKenna, D. Mennitt, M. Thompson, and S. Van Parijs, "Monitoring bio-acoustic activity & geospatial models of ambient sound: Applications in a marine sanctuary," Ecology and acoustics: emergent properties from community to landscape, Paris, France (2014).
C. Walker, S. Buxner, D. J. Mennitt, C. Cooper, S. O'Connor, and S. M. Pompea, "Using NGSS to Shape Research Projects with Citizen-Science Data," Astronomical Society of the Pacific Annual Meeting, Burlingame, California (2014).
D. J. Mennitt, K. Fristrup, and K. Sherrill, "A geospatial model of ambient sound pressure levels in the continental United States," The Journal of the Acoustical Society of America 132, 1926 (2012).
D. J. Mennitt, "Spatial variation of natural ambient sound pressure levels in Rocky Mountain National Park." The Journal of the Acoustical Society of America 129, 2617 (2011).
M. Ermann, J. Carneal, D. Mennitt, C. Jackson, B. Karmarkar, M. Helveston, and P. Clay, "Sound transmission loss of nontraditional building materials and redundancies," The Journal of the Acoustical Society of America 122(5) (2007).
D. J. Mennitt, M. Johnson, and J. Carneal, "Coarse classification of acoustic signals using temporal and spectral characteristics," Journal of the Acoustical Society of America 121(5):3046 (2007).
J. Carneal, M. Johnson, D. J. Mennitt, and P. Gillett, "Localization and tracking noise sources with autonomous vehicles: from node processing to central command fusion and tracking," Acoustical Society of America's North Carolina Chapter, Raleigh, NC (2006).
D. J. Mennitt, "Numerical accuracy of virtual acoustic prototyping: determination of the minimum size of the evaluation sphere to achieve accurate local simulation," Acoustical Society of America's North Carolina Chapter, Raleigh, NC (2006).
D. J. Mennitt, J. Redenshek, A. Tawney "Acoustical mapping of the lyric theater," Acoustical Society of America's North Carolina Chapter, Blacksburg, VA (2005).

Dan Mennitt

Project Experience

Publications

Peer Reviews

Patents