This review discusses the challenges in hearing aid design and fitting and the recent developments in advanced signal processing technologies to meet these challenges. The first part of the review discusses the basic concepts and the building blocks of digital signal processing algorithms, namely, the signal detection and analysis unit, the decision rules, and the time constants involved in the execution of the decision. In addition, mechanisms and the differences in the implementation of various strategies used to reduce the negative effects of noise are discussed. These technologies include the microphone technologies that take advantage of the spatial differences between speech and noise and the noise reduction algorithms that take advantage of the spectral difference and temporal separation between speech and noise. The specific technologies discussed in this paper include first-order directional microphones, adaptive directional microphones, second-order directional microphones, microphone matching algorithms, array microphones, multichannel adaptive noise reduction algorithms, and synchrony detection noise reduction algorithms. Verification data for these technologies, if available, are also summarized.

We present a general description of white-beam (Laue) scattering from grains with dislocations. This approach is applied to examples with equal numbers of positive and negative Burger’s vectors (paired) and with unpaired dislocations of one sign (geometrically necessary). We find that streaking of the Laue reflections is sensitive to both long-range geometrical rotations introduced by unpaired edge dislocations and to local rotation fluctuations introduced by the total number of dislocations (paired and unpaired). We demonstrate the technique by analyzing the dislocation distribution in a nanoindented Cu single crystal.

This study analyses the radiological and clinical results according to the two techniques of unilateral and bilateral balloon kyphoplasty in osteoporotic vertebral compression fractures. Fifty-two patients with osteoporotic vertebral compression fractures occurring at the thoracolumbar junction were enrolled in this study. All patients were classified into two groups; group I was treated with a unilateral approach and group II with a bilateral approach. The Cobb angle was measured each time to evaluate the kyphotic angle during the pre- and post-operative periods and at last follow-up, and a 10-point visual analog scale for pain was recorded at the same time. We found that the bilateral approach had a greater advantage in the reduction of kyphosis and the loss of reduction was less than the unilateral approach for the treatment of osteoporotic vertebral compression fractures.

Liver stiffness scores measured by FibroScan correlate well with the presence of esophageal or gastric varices. FibroScan is a novel, noninvasive, and useful screening method for the preendoscopic detection of varices in postoperative patients with BA.