Prevalence of hearing impairment among primary school children in the Kilimanjaro region within Tanzania.

Introduction: Hearing impairment is becoming a public health concern and a widespread problem. The World Health Organization estimates that globally there are about 466 million people with hearing impairment, of which 34 million represent children. We examined the prevalence and etiology of hearing impairment among primary school children in the Kilimanjaro region within Tanzania.

Low-loss ultrasound transmission through glass assisted by resonance.

We have investigated transmission of ultrasound signals from a speaker in air through a 400 µm thick borosilicate glass plate, similar to those found in consumer electronics products such as mobile phones and tablets. In order to enhance transmission, we took advantage of resonances in the glass plate and a cavity, which is placed between the glass and the microphone. The results show that it is possible to achieve transmission of a signal with bandwidth of approximately 5 kHz with less than -10 dB attenuation, and only -2 dB attenuation at the resonance peak frequency.

Statistical tool to detect small hearing threshold shifts.

Objective: The aim of this study is to present a new tool that can be used in the prevention of noise-induced hearing loss. Even in most countries where noise levels are well regulated, many workers are still exposed to high levels of noise and suffer from permanent threshold shifts. It is necessary to develop a new strategy to prevent such damage.

The efficacy of sound regulations on the listening levels of pop concerts.

This analysis of new and previously collected data was done to validate the efficacy of recommendations for limits regarding sound exposure levels at live pop concerts. After the World Health Organization (WHO) recommended limiting the sound levels at such concerts to avoid noise induced hearing damage among the audience, the actual levels at concerts where these recommendations are observed, have stabilized around 100 dBA. This is a level that is considered acceptable by WHO.