The NVL has always been focused on research-oriented projects, many of which are multi-disciplinary. Participating with other departments at WMU, some of these projects have seen great success. Here are a few of the more recent projects that involved undergraduate and graduate students:
Better long cane design and biomechanics for blind cane users
Dr. Naghshineh and MS-ME graduate student, Aaron Dean, are collaborating with Drs. Dae Kim and Robert Wall Emerson in the WMU Department of Blindness and Low Vision Studies, in order to study the relation between blind cane vibration characteristics and obstacle or drop-off detection. In this study, which is funded by National Institute of Health (NIH), the vibration properties of canes with different mass and stiffness were measured, then given to blind users who were tested in their ability to notice a drop-off in their path. Several instrumented canes have also been fabricated in order to measure cane vibration while it is in use for navigation. Identifying the cane characteristics that are most helpful to the user will allow the design of a safer, more reliable blind cane.
Integrating approaches from behavior and engineering to explore how male songbirds respond to anthropogenic noise
In a multi-disciplinary project, funded by the National Science Foundation (NSF), Drs. Naghshineh and Gill (of WMU’s Department of Biological Sciences) study how anthropogenic noise affects the habitual behavior of multiple species of songbirds. This work was conducted throughout the Kalamazoo area. Research assistants and employees of the Noise and Vibration Lab, Dr. Kyle Myers and Steve Beuerle, have helped in providing program support in form of data collection, sound file analysis, and equipment calibration for this project.
Wildlife Acoustic’s Song Meter 2 was the principal piece of equipment used for recording the songbirds’ activity. Using MATLAB, many different programs were written to aid calibration of these units and analysis of sound files from these units.
This ongoing study has resulted in multiple publications thus far and is continuing the study using different species of songbirds, and different habitats associated with each species. Variations of species, habitat, and song-activity have been studied in hopes to scientifically connect the presence of anthropogenic noise to the behavior of these songbirds.
Analysis of the vibroacoustic properties of dimpled structures
Structures such as steel plates are excited by sources in a variety of applications (e.g. washing machines, dishwashers, floors of trains) and produce unwanted noise to listeners. These vibrating structures can act like a large soundboard and produce potentially high levels of noise in the environment. Noise can be both annoying and damaging to listener’s hearing over sustained exposure. Fortunately, noise levels produced by vibrating structures can be reduced using a variety of methods. These methods often involve changing the way and the amount the structures vibrate. This research focuses on a newly emerging technique to quiet vibrating beams and plates by introducing dimples onto their surfaces. One or more dimples of various sizes can be positioned on the surface to design for a quiet structure. The dimples are able to shift the natural frequencies of the structure away from an excitation frequency so that large vibration amplitudes due to resonance are avoided. The dimples can also change the mode shapes of the structure to achieve a broadband noise reduction. Since dimples are already used in industry to stiffen structures, they are an attractive candidate for use in noise and vibration.
This is an ongoing project that has already resulted in the publication of one paper, Dr. Kyle Myers doctoral dissertation, which can be found here. Continuation of this work is the focus of Mofareh Ghazwani’s work.
Detection of hybrid and quiet vehicles by blind and visually impaired pedestrian
The increased popularity of hybrid electric vehicles has created a growing concern for the safety of blind and visually impaired pedestrians, because these vehicles typically emit lower sound levels when compared to internal combustion engine vehicles. Studies were performed in collaboration with GM and Nissan. The first phase of these studies showed that quiet cars are more difficult to detect when moving at low speeds, compared to traditional IC vehicles. The second phase investigated the kind of sound these cars should generate, and at what level, to help blind pedestrians detect the car.