The elimination of selected chronic diseases in a population: the compression and expansion of morbidity.

Abstract Background Compression and expansion of morbidity are two critical hypotheses to analyze the relationship among morbidity, disability, and mortality. This study aims to analyze the global distribution of the compression and expansion of morbidity and to investigate its relationship with income inequality. Methods Data was from the Global Burden of Disease Study 2016 and Standardized World Income Inequality Database, version 8.2. Seven types of health changes were defined. Income inequality was measured with Gini coefficient index. Binary logistic regression was used to analyze the association of income inequality with the compression and expansion of morbidity. Results All the seven types of the compression and expansion of morbidity exist in the world, despite their uneven distribution. The relative expansion of morbidity with increased or constant life expectancy (Type 6) was the most popular type occurring to more than half of populations in the last quarter of century, which was followed by the relative compression of morbidity with increased or constant LE (Type 3, 30.71%). The income inequality was significantly associated with the health changes, which still held after controlling a variety of confounders and in robustness tests. Those societies with lower income inequality were more likely to incur Type 3. Conclusions It is necessary to distinguish the positive and negative changes in life expectancy when examing the compression and expansion of morbidity. The increasing popularity of Type 6 implies higher needs for health and social care. Measures to reduce income inequality or mitigate its negative influence on health changes might promote the occurrence of Type 3.

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The Effect of Nonlinear Amplitude Growth on the Speech Perception Benefits Provided by a Single-Sided Vocoder

Journal of Speech Language and Hearing Research ◽

10.1044/2018_jslhr-h-18-0001 ◽

2019 ◽

Vol 62 (3) ◽

pp. 745-757 ◽

Cited By ~ 2

Author(s):

Jessica M. Wess ◽

Joshua G. W. Bernstein

Keyword(s):

Transfer Functions ◽

Spatial Configuration ◽

Free Field ◽

Spatial Separation ◽

Compression And Expansion ◽

Interaural Difference ◽

Interaural Differences ◽

Single Sided Deafness ◽

Perceptual Separation ◽

Loudness Growth

PurposeFor listeners with single-sided deafness, a cochlear implant (CI) can improve speech understanding by giving the listener access to the ear with the better target-to-masker ratio (TMR; head shadow) or by providing interaural difference cues to facilitate the perceptual separation of concurrent talkers (squelch). CI simulations presented to listeners with normal hearing examined how these benefits could be affected by interaural differences in loudness growth in a speech-on-speech masking task.MethodExperiment 1 examined a target–masker spatial configuration where the vocoded ear had a poorer TMR than the nonvocoded ear. Experiment 2 examined the reverse configuration. Generic head-related transfer functions simulated free-field listening. Compression or expansion was applied independently to each vocoder channel (power-law exponents: 0.25, 0.5, 1, 1.5, or 2).ResultsCompression reduced the benefit provided by the vocoder ear in both experiments. There was some evidence that expansion increased squelch in Experiment 1 but reduced the benefit in Experiment 2 where the vocoder ear provided a combination of head-shadow and squelch benefits.ConclusionsThe effects of compression and expansion are interpreted in terms of envelope distortion and changes in the vocoded-ear TMR (for head shadow) or changes in perceived target–masker spatial separation (for squelch). The compression parameter is a candidate for clinical optimization to improve single-sided deafness CI outcomes.

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