Directional Hearing Aid Design

In this proposal we describe our intent to build a directional hearing aid under the guidance of Professor Erik Cheever and E. Carr Everbach. Currently, there is a need for reliable and effective hearing aid designs and we will attempt to implement one given our undergraduate background in engineering. This project will demonstrate our interdisciplinary education at Swarthmore College through the construction of a directional hearing aid. This senior project will serve mainly as an educational demonstration of sound engineering principles and practice. Introduction The unavoidable presence of hearing loss and other aural impairments presents an opportunity for engineers to conceive solutions to benefit that segment of the population. In the past, many solutions have been implemented in analog circuitry. In 2003, Emily Eddy developed such a prototype that allows the wearer to receive more audibility in the direction she faces. Our goal is to further the design in a digital landscape that has several advantages over its analog equivalent, ultimately increasing the functionality of the device. This project is concerned with the robust design and implementation of a digital directional hearing aid. This proposal begins with a technical discussion of the underlying theory, processes, and benefits behind the device. It highlights the project progression and decisions made in the implementation. The project plan subsection further illustrates the proposed tasks in detail, and provides a timeline for anticipated completion. This is organized in the Critical Path Method (CPM) of project planning. The authors then list the relevant qualifications needed for a successful project completion. Finally a summary of required parts and their costs are provided. Technical Discussion Hearing loss impairment has long affected many people of all ages. Without sufficient hearing, people lose a valuable sense that can negatively affect their daily experiences. Examples include the exclusion from active family conversations, symphonic experiences, and limited awareness of surroundings. Thus the development of affordable and, more importantly, effective hearing aids is essential. First, one must have a sophisticated understanding of hearing perception and the effects at play in hearing loss. The frequency range of normal human hearing roughly spans from 20 to 20,000 Hertz. When one suffers from hearing loss, tiny hair follicles in the ear canal wear away, and decrease the upper end before the lower end of that range. This is typical of elderly people exhibiting normal hearing loss from increasing age.