Single-sided deafness (SSD) refers to a condition where there is severe to profound Sensorineural hearing loss in one ear, while the other ear has normal or near-normal hearing. SSD can significantly impact an individual's ability to localize sounds, understand speech in noisy environments, and maintain spatial awareness, often resulting in a reduced quality of life and increased social isolation. In children with unilateral deafness, it can impede spoken language development and potentially impact cognitive abilities. Historically, there was a misconception that the unaffected ear could adequately support speech development in early cases and provide acceptable hearing function in adults. Consequently, SSD was frequently undertreated. However, advances in technology and a deeper understanding of the psychological and developmental impact of SSD have led to a shift in management strategies. Various treatment options are available for addressing SSD, but ongoing debate surrounds the most effective approach. These options include cochlear implants (CI), contra-lateral-routing-of-signal (CROS) devices, and bone conduction devices (BCDs). The aim of this study is to review the scientific evidence on different treatment options for SSD and compare their impact on the quality of life of individuals with this condition.

Insulated Gate Bipolar Transistor (IGBT) may convey high current and sustain high breakdown voltages; it may provide high power control. In a sense, how IGBT demonstrates the capability of power control was not specifically described, and the equivalent bipolar junction transistors (BJT) activated by an applied bias to the insulated gate is intriguing. As seen in Figure 1, IGBT shows an equivalent circuit structure containing two types of BJT, (NPN-type Bipolar transistor and PNP-type Bipolar transistor), which can be modeled as diode-associated transistor. Apparently, as a bias applies to the controlling gate, the channel beneath the gate oxide gets strongly inversed and turns out to be conductive just like what happens on metal-oxide-silicon field effect transistor (MOSFET), which provides necessary igniting currents to both BJTs and thus causes high current gain flowing through them-selves from the bottom. A proposed and renewed formula provides addressing the above scenario and successfully fitting the measured data that forms the characteristic curves. Some parameters in the proposed formula, which includes size and mobility associated constant, threshold voltage, and Early-Voltage-related lambda for MOSFET, explain and explore the underlying physics. IGBT thus enjoy high input impedance and high current gain due to MOSFET (Insulated Gate) and BJT, respectively. This formula combines both merits of MOSFET and BJT in order to fit the measured data. Indeed, the formula intimately fits IGBT electrical characteristic curves, and thus may be qualified and served as a model. The new model is then advisable for designing power integrated circuit to exactly achieve power saving, power control, and power efficiency.