Even people with severe hearing impairment can now wear an almost invisible in-the-ear device — thanks to the world’s most powerful mini hearing aid. The Siemens Nitro is capable of volumes up to 70 decibels, which is roughly comparable to the normal volume of a TV set. The device is available in Germany and many European countries, with two amplifier models (55 decibels and 70 decibels). Previously, patients with such considerable hearing impairment have had to rely on behind-the-ear devices.