Abstract :
In the United States, approximately 15% of adults (37.5M) age 18 and over report some trouble hearing[1,2], 1 in 8 people (13%, or 30M) 12 years or older have hearing loss in both ears[2,3], and approximately 3 out of 1000 children are born with hearing loss[2,4]. Educating the public, especially K-12 students, on the dangers of hearing loss is important. The ability to develop both a physical model of the middle ear along with signal processing simulation of effective impulsive sound suppression for hearing aids/cochlear implants will help provide a useful, hands-on experience for student education. Today, a functioning model of the bones of the middle ear exhibiting movement, forces, and sound conduction that highlight the importance of the ear´s natural safety mechanism does not exist. This paper discusses the design of a standalone, interactive, and educational electro-mechanical model that exhibits the motion of the middle ear bones which include: (i) anatomical 3-bone configuration, (ii) fluid environment in the cochlea, and (iii) electrode stimulation to the auditory nerve cortex. This model has been assessed and approved by STEM/SEEC-UTDallas. To highlight the impact of noise protection on hearing, a complementary offline signal processing implementation is included to reduce the negative effects of impulsive-like sounds for cochlear implant users. An adaptable, mathematical relationship defines impulsive like sound conditions and reduces sound energy stimulated by the electrodes without reducing quality/intelligibility in the frequency ranges associated with speech. This algorithm was validated using a paired preference test, a quality test, and an intelligibility test to which the algorithm increased quality of sound by +18%.
