Effects of Expansion Algorithms on Speech Reception Thresholds

2008 ◽  
Vol 19 (02) ◽  
pp. 147-157 ◽  
Author(s):  
Christi L. Wise ◽  
Justin A. Zakis

Expansion is commonly used to reduce microphone noise and low-level environmental noises that can be annoying to hearing aid users. It may also improve or reduce the perception of low-level speech. This study assessed the impact of two expansion algorithms, single and multiple channel, on speech reception thresholds (SRT) with 10 hearing impaired listeners wearing hearing aids with ADRO® processing. The single-channel algorithm suppressed sounds below 45 dB A, while the multiple-channel algorithm suppressed sounds below the long-term average spectrum of speech at either 55 or 45 dB SPL. The mean HINT SRTs in quiet were 39.4, 40.7, 40.6, and 41.8 dB A without expansion, with single-channel expansion, and with multiple-channel expansion at expansion thresholds of 45 and 55 dB SPL, respectively. The difference in mean SRT was only statistically significant between no expansion and multiple-channel expansion at a 55 dB SPL threshold. A regression analysis between the change in individual SRT for each expansion condition and pure tone average hearing loss showed no correlation. Our calculations indicate that only those with exceptionally good hearing will find microphone noise audible. The current practice of prescribing expansion algorithms based on hearing thresholds alone is questioned, and other rationales are discussed. La expansión se utiliza comúnmente para reducir el ruido de los micrófonos y los ruidos ambientales de bajo nivel que pueden ser perturbadores para los usuarios de auxiliares auditivos. También puede mejorar o reducir la percepción de lenguaje a bajo voumen. Este estudio evaluó el impacto de dos algoritmos de expansión, de canal múltiple y el canal único, sobre los umbrales de recepción del lenguaje (SRT) con 10 sujetos hipoacúsicos utilizando auxiliares auditivos con procesamiento ADRO®. El algoritmo de canal único suprimió sonidos por debajo de 45 dB A, mientras que el algoritmo de canal múltiple suprimió sonidos por debajo del espectro promedio a largo plazo del lenguaje, a 55 ó 45 dB SPL, respectivamente. La diferencia en el SRT medio fue sólo estadísticamente significativa entre la no expansión y la expansión de canal múltiple a un umbral de 55 dB SPL. Un análisis de regresión no mostró correlación entre el cambio en los SRT individuales para cada condición de expansión y la pérdida auditiva promedio para tonos puros. Nuestros cálculos indican que solamente aquellos con una audición excepcionalmente buena encontrarán audible el ruido del micrófono. Se cuestiona la práctica actual de prescribir algoritmos de expansión con base sólo en umbrales auditivos, y se discuten otros razonamientos.

2021 ◽  
Author(s):  
Aristofanis Tsiringakis ◽  
Natalie Theeuwes ◽  
Janet Barlow ◽  
Gert-Jan Steeneveld

<p>The low-level jet (LLJ) is an important phenomenon that can affect (and is affected by) the turbulence in the nocturnal urban boundary layer (UBL). We investigate the interaction of a regional LLJ with the UBL during a 2-day period over London. Observations from two Doppler Lidars and two numerical weather prediction models (Weather Research & Forecasting model and UKV Met Office Unified Model) are used to compared the LLJ characteristics (height, speed and fall-off) between a urban (London) and a rural (Chilbolton) site. We find that LLJs are elevated (70m) over London, due to the deeper UBL, an effect of the increased vertical mixing over the urban area and the difference in the topography between the two sites. Wind speed and fall-off are slightly reduced with respect to the rural LLJ. The effects of the urban area and the surrounding topography on the LLJ characteristics over London are isolated through idealized sensitivity experiments. We find that topography strongly affects the LLJ characteristics (height, falloff, and speed), but there is still a substantial urban influence.</p>


2003 ◽  
Vol 129 (3) ◽  
pp. 248-254 ◽  
Author(s):  
Jack J. Wazen ◽  
Jaclyn B. Spitzer ◽  
Soha N. Ghossaini ◽  
José N. Fayad ◽  
John K. Niparko ◽  
...  

OBJECTIVES: The purpose of this study is to evaluate the effectiveness of Bone Anchored Cochlear Stimulator (BAHA) in transcranial routing of signal by implanting the deaf ear. STUDY DESIGN AND SETTINGS: Eighteen patients with unilateral deafness were included in a multisite study. They had a 1-month pre-implantation trial with a contralateral routing of signal (CROS) hearing aid. Their performance with BAHA was compared with the CROS device using speech reception thresholds, speech recognition performance in noise, and the Abbreviated Profile Hearing Benefit and Single Sided Deafness questionnaires. RESULTS: Patients reported a significant improvement in speech intelligibility in noise and greater benefit from BAHA compared with CROS hearing aids. Patients were satisfied with the device and its impact on their quality of life. No major complications were reported. CONCLUSION AND SIGNIFICANCE: BAHA is effective in unilateral deafness. Auditory stimuli from the deaf side can be transmitted to the good ear, avoiding the limitations inherent in CROS amplification.


2014 ◽  
Vol 25 (02) ◽  
pp. 154-163 ◽  
Author(s):  
K. Jonas Brännström ◽  
Johannes Lantz ◽  
Lars Holme Nielsen ◽  
Steen Østergaard Olsen

Background: Outcome measures can be used to improve the quality of the rehabilitation by identifying and understanding which variables influence the outcome. This information can be used to improve outcomes for clients. In clinical practice, pure-tone audiometry, speech reception thresholds (SRTs), and speech discrimination scores (SDSs) in quiet or in noise are common assessments made prior to hearing aid (HA) fittings. It is not known whether SRT and SDS in quiet relate to HA outcome measured with the International Outcome Inventory for Hearing Aids (IOI-HA). Purpose: The aim of the present study was to investigate the relationship between pure-tone average (PTA), SRT, and SDS in quiet and IOI-HA in both first-time and experienced HA users. Research Design: SRT and SDS were measured in a sample of HA users who also responded to the IOI-HA. Study Sample: Fifty-eight Danish-speaking adult HA users. Data Collection and Analysis: The psychometric properties were evaluated and compared to previous studies using the IOI-HA. The associations and differences between the outcome scores and a number of descriptive variables (age, gender, fitted monaurally/binaurally with HA, first-time/experienced HA users, years of HA use, time since last HA fitting, best ear PTA, best ear SRT, or best ear SDS) were examined. A multiple forward stepwise regression analysis was conducted using scores on the separate IOI-HA items, the global score, and scores on the introspection and interaction subscales as dependent variables to examine whether the descriptive variables could predict these outcome measures. Results: Scores on single IOI-HA items, the global score, and scores on the introspection (items 1, 2, 4, and 7) and interaction (items 3, 5, and 6) subscales closely resemble those previously reported. Multiple regression analysis showed that the best ear SDS predicts about 18–19% of the outcome on items 3 and 5 separately, and about 16% on the interaction subscale (sum of items 3, 5, and 6) Conclusions: The best ears SDS explains some of the variance displayed in the IOI-HA global score and the interaction subscale. The relation between SDS and IOI-HA suggests that a poor unaided SDS might in itself be a limiting factor for the HA rehabilitation efficacy and hence the IOI-HA outcome. The clinician could use this information to align the user’s HA expectations to what is within possible reach.


2005 ◽  
Vol 16 (07) ◽  
pp. 515-522 ◽  
Author(s):  
David Fabry

This paper compares the evidence-based outcomes between cochlear implants and hearing aids during the past several decades. Despite many similarities, there are also some important differences that define the progress for the two disciplines. Perhaps the most significant distinction exists in terms of the difference between the Food and Drug Administration's treatment of hearing aids as Class I medical devices, while cochlear implants are defined as Class III devices. Another point of divergence has been the number of publications in archival, peer-reviewed journals; implant papers have been steadily increasing during the past decade, while hearing aid papers have declined during the same period. The impact of these differences on the past, present, and future of hearing aid and cochlear implant research, technology, and clinical practice is discussed.


2020 ◽  
Author(s):  
Beth Dingley ◽  
Guy Dagan ◽  
Philip Stier

<p>The phenomenon of convective aggregation in idealised radiative convective equilibrium simulations has the ability to change the mean state of its domain. When compared to non-aggregation conditions, these simulations usually have warmer drier mean atmospheres, with stronger precipitation in the convective areas. Many of these idealised experiments use a fixed sea surface temperature (SST), where higher temperatures generally increase the scale of aggregation. SST gradients have been shown to organise convection, yet there has been no work done to investigate the impact of heating perturbations in the air on the aggregation of convection. Here we investigate how strong diabatic heating of the atmospheric column affect the existence and properties of convective aggregation. These perturbations provide a link to studying the effect of large pollution plumes on convection, for example during the Indian monsoon season.</p><p>An aerosol model is used to insert plumes of strongly absorbing aerosols into aquaplanet, non-rotating, global RCE simulations. We study the sensitivity of the response to aerosol optical depth (AOD) and aerosol radiative properties under different SSTs.</p><p>Without any forcing, the simulations at low SST do not aggregate while at high SST they do. We also see that adding the forcing causes aggregation at both temperatures for a wide range of AODs. Detailed investigation shows that the diabatic heating source causes two circulations to develop, one with low-level convergence towards the plume and high-level divergence away from the plume. A secondary circulation works tangentially to the plume, again with low-level convergence and high-level divergence, driving the formation of several radial branches of aggregated convection. We argue that, as we see this aggregation for plumes with realistic AODs, this could be an analogue for real-world organisation during high pollution events. Future work will investigate the difference in mechanisms between forced and unforced convective aggregation as well as conducting similar experiments in smaller, cloud resolving domains.</p>


1986 ◽  
Vol 51 (4) ◽  
pp. 362-369 ◽  
Author(s):  
Donna M. Risberg ◽  
Robyn M. Cox

A custom in-the-ear (ITE) hearing aid fitting was compared to two over-the-ear (OTE) hearing aid fittings for each of 9 subjects with mild to moderately severe hearing losses. Speech intelligibility via the three instruments was compared using the Speech Intelligibility Rating (SIR) test. The relationship between functional gain and coupler gain was compared for the ITE and the higher rated OTE instruments. The difference in input received at the microphone locations of the two types of hearing aids was measured for 10 different subjects and compared to the functional gain data. It was concluded that (a) for persons with mild to moderately severe hearing losses, appropriately adjusted custom ITE fittings typically yield speech intelligibility that is equal to the better OTE fitting identified in a comparative evaluation; and (b) gain prescriptions for ITE hearing aids should be adjusted to account for the high-frequency emphasis associated with in-the-concha microphone placement.


2019 ◽  
pp. 109-123
Author(s):  
I. E. Limonov ◽  
M. V. Nesena

The purpose of this study is to evaluate the impact of public investment programs on the socio-economic development of territories. As a case, the federal target programs for the development of regions and investment programs of the financial development institution — Vnesheconombank, designed to solve the problems of regional development are considered. The impact of the public interventions were evaluated by the “difference in differences” method using Bayesian modeling. The results of the evaluation suggest the positive impact of federal target programs on the total factor productivity of regions and on innovation; and that regional investment programs of Vnesheconombank are improving the export activity. All of the investments considered are likely to have contributed to the reduction of unemployment, but their implementation has been accompanied by an increase in social inequality.


2020 ◽  
Vol 4 (2) ◽  
pp. 150
Author(s):  
Farzana Sharmin Pamela Islam

As 21st century is the era of modern technologies with different aspects, it offers us to make the best use of them. After tape recorder and overhead projector (OHP), multimedia has become an important part of language classroom facilities for its unique and effective application in delivering and learning lesson. Although in many parts of Bangladesh, a South Asian developing country, where English enjoys the status of a foreign language, the use of multimedia in teaching and learning is viewed as a matter of luxury. However, nowadays the usefulness and the necessity of it are well recognized by the academics as well as the government. The study aims to focus on the difference between a traditional classroom void of multimedia and multimedia equipped classrooms at university level by explaining how multimedia support the students with enhanced opportunity to interact with diverse texts that give them more in-depth comprehension of the subject. It also focuses on audio-visual advantage of multimedia on the students’ English language learning. The study has followed a qualitative method to get an in-depth understanding of the impact of using multimedia in an English language classroom at tertiary level. For this purpose, the data have been collected from two different sources. Firstly, from students’ written response to  an open ended question as to their comparative experience of learning  lessons with and without multimedia facilities; and secondly, through  observation of English language classes at a private university of Dhaka, the capital city of Bangladesh. The discussion of the study is limited to  the use of multimedia in English language classroom using cartoons, images and music with a view to enhance students’ skills in academic writing, critical analysis of image and critical appreciation of music. For this purpose, cartoons in English language, images from Google and music from You Tube have got focused discussion in this paper.


2020 ◽  
Vol 68 (4) ◽  
pp. 303-314
Author(s):  
Yuna Park ◽  
Hyo-In Koh ◽  
University of Science and Technology, Transpo ◽  
University of Science and Technology, Transpo ◽  
University of Science and Technology, Transpo ◽  
...  

Railway noise is calculated to predict the impact of new or reconstructed railway tracks on nearby residential areas. The results are used to prepare adequate counter- measures, and the calculation results are directly related to the cost of the action plans. The calculated values were used to produce noise maps for each area of inter- est. The Schall 03 2012 is one of the most frequently used methods for the production of noise maps. The latest version was released in 2012 and uses various input para- meters associated with the latest rail vehicles and track systems in Germany. This version has not been sufficiently used in South Korea, and there is a lack of standard guidelines and a precise manual for Korean railway systems. Thus, it is not clear what input parameters will match specific local cases. This study investigates the modeling procedure for Korean railway systems and the differences between calcu- lated railway sound levels and measured values obtained using the Schall 03 2012 model. Depending on the location of sound receivers, the difference between the cal- culated and measured values was within approximately 4 dB for various train types. In the case of high-speed trains, the value was approximately 7 dB. A noise-reducing measure was also modeled. The noise reduction effect of a low-height noise barrier system was predicted and evaluated for operating railway sites within the frame- work of a national research project in Korea. The comparison of calculated and measured values showed differences within 2.5 dB.


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