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Objectives: Globally, less than 1% of people who could benefit from a cochlear implant have one and the problem is particularly acute in lower-income countries. Here we give a narrative review of the economic and logistic feasibility of cochlear implant programmes in lower-income countries and discuss future developments that would enable better healthcare. We review the incidence and aetiology of hearing loss in low- and middle-income countries, screening for hearing loss, implantation criteria, issues concerning imaging and surgery, and the professional expertise required. We also review the cost of cochlear implantation and ongoing costs. Findings: The cost effectiveness of cochlear implants in lower-income countries is more limited by the cost of the device than the cost of surgery, but there are also large ongoing costs that will deter many potential users. Conclusions: We conclude that the main barriers to the future uptake of cochlear implants are likely to be logistical rather than technical and cochlear implant provision should be considered as part of a wider programme to improve the health of those with hearing loss. [ABSTRACT FROM AUTHOR]

Constant acceleration is usually demonstrated using gravity either on inclined planes, in free fall or with Atwood machines but this often leads to misunderstandings because students do not properly conceptualize gravity. A solution for demonstrating constant acceleration is a modified fan cart using the PASCO Dynamics cart which has low friction, can maintain a reasonably constant acceleration, has a strong spring bumper and can carry masses. Four possible experiments are included.

Force probes have opened up many possibilities for teaching physics students the relationship between force, acceleration and velocity. In one experiment that a group of high school physics found useful, a force probe was mounted on a minature wheeled cart and secured to a stationary track via rubber bands. In this configuration, the force probe was used to measured the instananeous net force on the cart, while an ultrasonic position detector measured position, velocity and acceleration. The relationship between force and acceleration was made clear by simultaneously graphing using MacMotion software and a Universal Lab Interface with a Macintosh SE computer.