The Effects of Altered Auditory Feedback (AAF) on Fluency in Adults Who Stutter: A Systematic Review

Background and Objectives: Stuttering affects 70 million people worldwide, which is about 1% of the population. Altered auditory feedback (AAF) is a process by which an individual’s auditory speech signal is electronically changed to temporarily increase the fluency of a person who stutters. For the purpose of this systematic review, AAF includes delayed auditory feedback (DAF) and frequency-altered feedback (FAF). This systematic review examines fluency enhancement in adults who stutter when using AAF devices. Methods: A review of the literature was searched using PubMed, Ovid MEDLINE, PsycINFO, and CINAHL databases with key search terms related to stuttering and AAF. Inclusion criteria included: 1) adults ages ≥ 18 years old who stutter, 2) comparison of altered auditory feedback forms and/or no altered auditory feedback forms in the treatment of stuttering, 3) inclusion of DAF or FAF, 4) outcomes related to aspects of stuttering or people who stutter (e.g., fluency level, speech naturalness, speech rate), and 5) experimental research. Studies were quality assessed and rated by the authors. Results: A total of 16 articles were included in this review. Articles were of ‘moderate’ quality. Conclusions: AAF devices are generally effective in reducing stuttering frequency, with most notable fluency enhancement occurring during oral reading. The degree of fluency enhancement between individuals who stutter is variable and is influenced by factors such as stuttering severity. While research generally supports the use of AAF devices in reducing stuttering frequency, there are inconsistent findings regarding speech naturalness. AAF is likely most effective when used in conjunction with traditional speech therapy. Further research is needed to better understand the relationship between AAF and stuttering, particularly regarding unstructured speaking tasks and speech naturalness.https://scholarworks.uvm.edu/csdms/1004/thumbnail.jp

Instantaneous sea ice drift speed from TanDEM-X interferometry

The drift of sea ice is an important geophysical process with widespread implications for the ocean energy budget and ecosystems. Drifting sea ice can also threaten marine operations and present a hazard for ocean vessels and installations. Here, we evaluate single-pass along-track synthetic aperture radar (SAR) interferometry (S-ATI) as a tool to assess ice drift while discussing possible applications and inherent limitations. Initial validation shows that TanDEM-X phase-derived drift speed corresponds well with drift products from a ground-based radar at Utqiagvik, Alaska. Joint analysis of TanDEM-X and Sentinel-1 data covering the Fram Strait demonstrates that S-ATI can help quantify the opening/closing rate of leads with possible applications for navigation. S-ATI enables an instantaneous assessment of ice drift and dynamic processes that are otherwise difficult to observe. For instance, by evaluating sea ice drift through the Vilkitsky Strait, Russia, we identified short-lived transient convergence patterns. We conclude that S-ATI enables the identification and analysis of potentially important dynamic processes (e.g., drift, rafting, and ridging). However, current limitations of S-ATI are significant (e.g., data availability and they presently only provide the cross-track vector component of the ice drift field) but may be significantly reduced with future SAR systems

Instantaneous sea ice drift speed from TanDEM-X interferometry

The drift of sea ice is an important geophysical process with widespread implications for the ocean energy budget and ecosystems. Drifting sea ice can also threaten marine operations and present a hazard for ocean vessels and installations. Here, we evaluate single-pass along-track synthetic aperture radar (SAR) interferometry (S-ATI) as a tool to assess ice drift while discussing possible applications and inherent limitations. Initial validation shows that TanDEM-X phase-derived drift speed corresponds well with drift products from a ground-based radar at Utqiaġvik, Alaska. Joint analysis of TanDEM-X and Sentinel-1 data covering the Fram Strait demonstrates that S-ATI can help quantify the opening/closing rate of leads with possible applications for navigation. S-ATI enables an instantaneous assessment of ice drift and dynamic processes that are otherwise difficult to observe. For instance, by evaluating sea ice drift through the Vilkitsky Strait, Russia, we identified short-lived transient convergence patterns. We conclude that S-ATI enables the identification and analysis of potentially important dynamic processes (e.g., drift, rafting, and ridging). However, current limitations of S-ATI are significant (e.g., data availability and they presently only provide the cross-track vector component of the ice drift field) but may be significantly reduced with future SAR systems.</p

The Inner-Shelf Dynamics Experiment

17 USC 105 interim-entered record; under review.The article of record as published may be found at http://dx.doi.org/10.1175/BAMS-D-19-0281.1The inner shelf, the transition zone between the surfzone and the midshelf, is a dynamically complex region with the evolution of circulation and stratification driven by multiple physical processes. Cross-shelf exchange through the inner shelf has important implications for coastal water quality, ecological connectivity, and lateral movement of sediment and heat. The Inner-Shelf Dynamics Experiment (ISDE) was an intensive, coordinated, multi-institution field experiment from September–October 2017, conducted from the midshelf, through the inner shelf, and into the surfzone near Point Sal, California. Satellite, airborne, shore- and ship-based remote sensing, in-water moorings and ship-based sampling, and numerical ocean circulation models forced by winds, waves, and tides were used to investigate the dynamics governing the circulation and transport in the inner shelf and the role of coastline variability on regional circulation dynamics. Here, the following physical processes are highlighted: internal wave dynamics from the midshelf to the inner shelf; flow separation and eddy shedding off Point Sal; offshore ejection of surfzone waters from rip currents; and wind-driven subtidal circulation dynamics. The extensive dataset from ISDE allows for unprecedented investigations into the role of physical processes in creating spatial heterogeneity, and nonlinear interactions between various inner-shelf physical processes. Overall, the highly spatially and temporally resolved oceanographic measurements and numerical simulations of ISDE provide a central framework for studies exploring this complex and fascinating region of the ocean.U.S. Office of Naval Research (ONR)ONR Departmental Research Initiative (DRI)Inner-Shelf Dynamics Experiment (ISDE

A new scalloping filter algorithm for scansar images

Due to its specific way of scanning over multiple sub-swaths of a radar image, a ScanSAR (scanning synthetic aperture radar) cannot sample Doppler histories continuously like a regular SAR in stripmap mode. This can cause an artifact known as azimuthal scalloping, a wave-like modulation of the image intensity in azimuth direction. Although the problem is theoretically understood, many ScanSAR images of ocean scenes continue to exhibit scalloping. This hampers their use for applications such as wave and wind retrievals. We have developed an efficient descalloping algorithm that can be applied to such images as a post-processing tool. We describe how it works and show examples

Intercomparison and validation of bathymetry radar imaging models

Multi-frequency airborne SAR data over a submerged reef, with very large associated surface current variations, are compared with model calculations, using a wide variety in models and parametrizations. It is concluded that all models still underestimate the measured contrasts, that detailed differences in models cannot be validated due to speckle and non-bathymetric features, and that L-band is more suited for bathymetry applications than C- or X-band

Mapping of tidal currents with SAR along track interferometry

An update of the status of SAR Along Track Interferometry (ATI) is given and examples from X-SAR/SRTM for the waters around the Orkney Islands are provided. A special InSAR "Ocean-Processor" is described. The derived SRTM "velocity maps" demonstrate how valuable this method can be for a world-wide mapping of tidal ocean currents and for the detection of promising sites for hydropower installation