The Auditory Skills Necessary for Echolocation: A New Explanation

1996 ◽  
Vol 90 (1) ◽  
pp. 21-35 ◽  
Author(s):  
C. Carlson–Smith ◽  
W.R. Wiener

The study presented here explored theories that account for echolocation and established an audiometric test battery for blind persons that is designed to predict success in echolocation. Statistical analyses revealed significant positive correlations between particular auditory measures and echolocation performance. No relationships were found between high-frequency hearing sensitivity and echolocation performance.

2017 ◽  
Vol 284 (1864) ◽  
pp. 20171670 ◽  
Author(s):  
Molly C. Womack ◽  
Jakob Christensen-Dalsgaard ◽  
Luis A. Coloma ◽  
Juan C. Chaparro ◽  
Kim L. Hoke

Sensory losses or reductions are frequently attributed to relaxed selection. However, anuran species have lost tympanic middle ears many times, despite anurans' use of acoustic communication and the benefit of middle ears for hearing airborne sound. Here we determine whether pre-existing alternative sensory pathways enable anurans lacking tympanic middle ears (termed earless anurans) to hear airborne sound as well as eared species or to better sense vibrations in the environment. We used auditory brainstem recordings to compare hearing and vibrational sensitivity among 10 species (six eared, four earless) within the Neotropical true toad family (Bufonidae). We found that species lacking middle ears are less sensitive to high-frequency sounds, however, low-frequency hearing and vibrational sensitivity are equivalent between eared and earless species. Furthermore, extratympanic hearing sensitivity varies among earless species, highlighting potential species differences in extratympanic hearing mechanisms. We argue that ancestral bufonids may have sufficient extratympanic hearing and vibrational sensitivity such that earless lineages tolerated the loss of high frequency hearing sensitivity by adopting species-specific behavioural strategies to detect conspecifics, predators and prey.


Biology ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 699
Author(s):  
Rashmi Supriya ◽  
Fei-Fei Li ◽  
Yi-De Yang ◽  
Wei Liang ◽  
Julien S. Baker

Background: the clustering of metabolic syndrome (MetS) risk factors is becoming more prevalent in children, leading to the development of type 2 diabetes (T2D) and cardiovascular diseases in early adulthood. The impact of MetS risk factors on cardiac autonomic modulation (CAM) or vice versa has been noted to track from childhood to pre-adolescence and adolescence. Understating associations in this age group may help to improve the clinical outcomes of the MetS, even when MetS symptoms are not visible. Potential damage from each individual MetS component and the ability to predict early cardiac damage or upcoming cardiovascular events is very important. Therefore, the present systematic review and meta-analysis investigated the associations between CAM and MetS risk factors individually to verify which of the MetS risk components were significantly correlated with heart rate variability (HRV) indices before or at the onset of the MetS among young people. The purpose of this review was to outline the importance of potentially screening HRV indices in young people even with only one MetS risk factor, as a pre-indicator for early cardiovascular risk stratification. Methods: cross-sectional studies that examined the relationship of MetS risk factors with HRV indices were searched using four databases including PubMed, the Cochrane clinical trials library, Medline and the Web of Science. Correlation coefficients with 95% confidence intervals (95% CI), and random effects meta-analyses of the association between MetS risk factors with HRV indices were performed. Results: out of 14 cross-sectional studies and one case-control study, 8 studies (10 data sets) provided association data for the meta-analysis. Our results indicated significant positive correlations for systolic blood pressure (SBP) (correlation coefficient 0.13 (95%CI: 0.06; 0.19), I2 = 47.26%) and diastolic blood pressure (DBP) (correlation coefficient 0.09 (95%CI: −0.01; 0.18), I2 = 0%) with a Low Frequency/High Frequency ratio (LF/HF). Significant negative correlations for waist circumference (WC) (correlation coefficient −0.12 (95%CI: −0.19; −0.04), I2 = 51.50%), Triglycerides (TGs) (correlation coefficient −0.09 (95%CI: −0.15; −0.02), I2 = 0%) and ≥2 MetS risk factors (correlation coefficient −0.10 (95%CI: −0.16; −0.03), I2 = 0%); with high frequency (HF) were revealed. Significant positive correlations for high density lipoprotein (HDL) (correlation coefficient 0.08 (95%CI: 0.05; 0.11), I2 = 0%) and significant negative correlations of ≥2 MetS risk (correlation coefficient −0.04 (95%CI: −0.12; 0.03), I2 = 0.0%) with low frequency (LF) were revealed. Significant negative correlations for TGs (correlation coefficient −0.09 (95%CI: −0.23; 0.05), I2 = 2.01%) with a mean square root of the sum of differences between mean time between two successive intervals (rMSSD) and significant positive correlation of HDL (correlation coefficient 0.09 (95%CI: −0.01; 0.19), I2 = 0.33%) with standard deviation of the time between two successive intervals (SDNN) were also revealed. An Egger’s test indicated that there was no obvious publication bias for any of the above relationships except for TGs and rMSSD. The significance level stipulated for the meta-analysis was p < 0.05. Conclusions: lipid profiles (HDL and TGs), WC and BP were associated with CAM in young people up to the age of 19 years. The use of HRV indices to predict future MetS risk, and relationships with individual risk factors including HDL, BP, WC and TGs, were established. Future studies related to young people (up to the age of 19 years) are recommended to explore the associations reported here further.


2016 ◽  
Vol 27 (1) ◽  
pp. 3-7
Author(s):  
Suchetha Rao ◽  
Ranjith Kumar ◽  
Jayashree Bhat ◽  
Nutan Kamath

Context: Vincristine chemotherapy has dose dependent ototoxicity. Early detection of ototoxicity is better with otoacoustic emissions and high frequency audiometry than conventional pure tone audiometry. The study was done to see if vincristine treatment interferes with hearing sensitivity in children.Methods and Material: A prospective study was conducted on twenty-three children with acute lymphoblastic leukemia (ALL) on Multi Center Protocol (MCP 841).These were subjected to conventional audiometry, high frequency audiometry and distortion product otoacoustic emissions (DPOAEs) before starting chemotherapy. The follow up audiological evaluation after early intensive phase chemotherapy (approximately 6 months) was conducted in thirteen children, who received 12 doses of vincristine (1.4 mg/m2), cranial irradiation of 1800cGy (>3 years) as per protocol and antibiotics as per clinical demands.Results: Baseline audiological evaluation was normal. Follow-up evaluation DPOAEs showed a declining tendency, however changes did not reach statistical significance. Differences in median hearing thresholds prior and post treatment in higher frequency audiometry were also minimal which was not statistically significant. Conventional audiometric thresholds were not altered.Conclusions: The reduction in the signal noise ratio of DPOAE, and reduced hearing sensitivity in high frequencies in post chemotherapy in comparison with baseline measures cannot be ignored though it has failed to reach the level of statistical significance. children on vincristine should have a pre chemotherapy and follow up audiological evaluation with DPOAE The results of the present study needs to be strengthened by including larger sample and long term follow up.Bangladesh J Medicine Jan 2016; 27(1) : 3-7


2009 ◽  
Vol 55 (1) ◽  
pp. 11-30 ◽  
Author(s):  
Gili Peleg ◽  
Gadi Katzir ◽  
Ofer Peleg ◽  
Michal Kamara ◽  
Leonid Brodsky ◽  
...  

Most of the studies comparing facial expressions of born blind and sighted persons that have been carried out up until now have involved children as subjects. Various studies claimed that the quantity and quality of facial expressions of congenitally blind persons deteriorate with increasing age. Here, we compared facial expressions of born blind and sighted individuals using adults predominantly. Facial expressions were documented in an individual interview inducing such emotions as think-concentrate, sadness, anger, disgust, joy, and surprise.Common characteristics found amongst studied individuals were: similar repertoires*of movements over the entire interview, high-frequency and high-repertoire proportion of facial movements in concentration, sadness, and anger relative to those in disgust, joy, and surprise, similar distributions of a cumulative repertoire proportion of facial movements, and also common behavioral profiles of frequencies of facial movements in the emotional states discussed. Similar displays of eyebrow movements were found as well in concentration, sadness, and anger.Our study indicates that most tested characteristics of facial movements are common to born blind and sighted subjects, except for different cumulative mean frequencies in different emotional states, which is possibly related to the lack of visual feedback in born blind persons.Our study substantiates the hypothesis that facial expressions are innate and have important cues in the evolution of social communication.


1976 ◽  
Vol 102 (11) ◽  
pp. 654 ◽  
Author(s):  
Jack D. Clemis ◽  
Patricia G. Mastricola

1979 ◽  
Vol 87 (6) ◽  
pp. 871-875 ◽  
Author(s):  
Geary A. McCandless ◽  
James L. Parkin

This study investigated hearing aid acceptance and use as functions of the probable site of a lesion: conductive, cochlear, neural, and central as determined by an audiometric test battery. Results indicate significantly better acceptance of aids in conductive and cochlear disorders than in more central neural and central disorders.


1974 ◽  
Vol 39 (3) ◽  
pp. 320-329 ◽  
Author(s):  
Arthur J. Dahle ◽  
Faye P. McCollister ◽  
Barbara A. Hamner ◽  
David W. Reynolds ◽  
Sergio Stagno

The hearing sensitivity of children with subclinical congenital cytomegalovirus infection was evaluated and compared with that of a group of matched control subjects. Nine of the 18 infected subjects had some hearing loss, ranging from slight high-frequency impairments to a severe-to-profound unilateral loss. The findings indicate that subclinical congenital cytomegalovirus must be considered a potential etiological factor in sensorineural hearing impairment.


Author(s):  
Б.И. Кузник ◽  
Ю.Н. Смоляков ◽  
Е.С. Гусева ◽  
С.О. Давыдов ◽  
И.В. Файн

Цель исследования - выявление взаимосвязи между показателями вариабельности сердечного ритма (ВСР), кровяным давлением и гемодинамическими функциями у женщин, страдающих гипертонической болезнью (ГБ) и находящихся на медикаментозной терапии (ГБ-1), либо в дополнение к этому, проходящих регулярные курсы кинезитерапии (ГБ-2). Методика. Наблюдения проведены на 72 женщинах, страдающих артериальной гипертензией II стадии. В группу ГБ-1 вошли 37 женщин с ГБ, находящихся на медикаментозной терапии, в группу ГБ-2 - 35 женщин с ГБ, которые, помимо медикаментозной терапии, регулярно проходили на протяжении 2-3 лет по 3-4 полуторамесячных курса кинезитерапии (управляемые умеренные физические нагрузки). Для изучения гемодинамики был использован датчик динамического рассеяния света (miniature Dynamic Light Scattering - mDLS) от Elfi-Tech (Rehovot, Israel), измеряющий сигналы, инициированные кожным кровотоком, и использующий методику разложения сигнала на частотные компоненты, связанные с разными гемодинамическими источниками. Из пульсовой компоненты mDLS сигнала извлекалась информация о вариабельности RR-интервалов и рассчитывались индикаторы вариабельности сердечного ритма. Введен показатель «гемодинамический индекс» (Hemodynamic Index - HI). Зависимость HI от скорости сдвига интерпретируется путем сопоставления каждой полосе частот определенной скорости сдвига (HI1 - низкочастотный, HI2 - промежуточный, HI3 - высокочастотный). Использованы следующие относительные (RHI, Relative Hemodynamic Index) и осцилляторные (OHI, Oscillatory Hemodynamic Indexes) гемодинамические индексы: нейрологический (NEUR), Майера (MAYER), дыхательный (RESP) и пульсовой (PULSE). ВСР показатели включали: HR (Heart Rate), PWR (Power) - общую мощность колебаний, LF (Low Frequency), HF (High Frequency), SDNN (Standard Deviation of the Normal-to-Normal), RMSSD (Root Mean Square of the Successive Differences), а также индексы: CVI (Cardiac Vagal Index) и CSI (Cardiac Sympathetic Index). Результаты. У женщин, находящихся исключительно на медикаментозной терапии (ГБ-1), выявляются отрицательные взаимосвязи LF и LF/HF с систолическим, средним и пульсовым давлением. При ГБ-2 проявляются отрицательные связи PWR, LF, HF с пульсовым давлением. При ГБ-1 обнаружены положительные взаимосвязи между HR и гемодинамическими индексами HI1, RHI2 и отрицательная взаимосвязь с RHI3, а также между RMSSD и RHI3 и между HF и HI1/HI3. У пациенток ГБ-2 обнаружена отрицательная корреляция SDNN и RHI1, а также PWR и RHI1; положительные взаимосвязи между PWR и HI2, HI3, RHI2, HF и RHI3 и LF/HF с HI1/HI3; отрицательные связи HF c HI1/HI3 и с RHI1, а также между LF/HF и RHI3, CSI и RHI3. У больных ГБ-1 имеются прямые связи между SDNN, PWR, LF, HF, CVI и NEUR_HI1, что свидетельствует о действии этих факторов на эндотелиальный кровоток (HI1). В группе ГБ-2 установлено наличие лишь положительных связей между LF, HF и NEUR_HI3. У больных ГБ-1 на уровень АД влияют все без исключения осцилляторные ритмы, которые могут оказывать как отрицательное (с MAYER_HI1, PULSE_HI2), так и положительное (MAYER_HI2, RESP_HI3) влияние. У больных ГБ-2 взаимосвязи АД с осцилляторными индексами не обнаружены. Заключение. Уменьшение в группе ГБ-2 по сравнению с больными группы ГБ-1 числа факторов, влияющих на АД и гемодинамику, носит более совершенный и благоприятный характер, что и обеспечивает более быструю и устойчивую нормализацию артериального давления. Aim. To study the relationship between heart rate variability (HRV), blood pressure and hemodynamic functions in women with essential hypertension (EH) receiving a drug therapy alone (EH-1) or in combination with regular courses of kinesitherapy (EH-2). Methods. The study included 72 women with EH. The EH-1 group consisted of 37 women with stage II arterial hypertension. The EH-2 group consisted of 35 women with stage II arterial hypertension who underwent 3-4 1.5-month courses of kinesitherapy (controlled moderate physical activity) on a regular basis for 2-3 years. Hemodynamics was studied with a miniature Dynamic Light Scattering (mDLS) sensor from Elfi-Tech (Rehovot, Israel), which measures signals initiated by the skin blood flow by decomposing the signal into frequency components associated with different hemodynamic sources. Information on the RR interval variability was extracted from the pulse component of mDLS signal, and indicators of heart rate variability were calculated. A Hemodynamic Index (HI) was introduced. The HI dependence on shear rate was interpreted by matching each frequency band with a specific shear rate (HI1, low-frequency; HI2, intermediate; HI3, high-frequency). The following relative (RHI, Relative Hemodynamic Index) and oscillatory (OHI, Oscillatory Hemodynamic Indexes) indexes were used: neurological (NEUR), Mayer (MAYER), respiratory (RESP), and pulse (PULSE) ones. The HRV indexes included HR (Heart Rate), PWR (Power, total oscillation power), LF (Low Frequency), HF (High Frequency), SDNN (Standard Deviation of the Normal-to-Normal), RMSSD (Root Mean Square of the Successive Differences). CVI (Cardiac Vagal Index), and CSI (Cardiac Sympathetic Index). Results. In women who were on drug therapy alone (EH-1), negative relationships were found for LF and LF/HF with systolic, mean and pulse pressure. For EH-2, PWR, LF, and HF negatively correlated with pulse pressure. For EH-1, HR positively correlated with the hemodynamic indices HI1 and RHI2 and negatively correlated with RHI3; RMSSD negatively correlated with RHI3; and HF negatively correlated with HI1/HI3. For patients with EH-2, negative correlations were observed for SDNN and RHI1, PWR and RHI1; positive correlations were found between PWR and HI2; HI3, RHI2, HF and RHI3; and between LF/HF and HI1/HI3. HF negatively correlated with HI1/HI3 and with RHI1. LF/HF negatively correlated with RHI3, and CSI negatively correlated with RHI3. In patients with EH-1, SDNN, PWR, LF, HF, CVI, and NEUR_HI1 were directly related, which indicated an effect of these factors on the endothelial blood flow (HI1). In the EH-2 group, only positive correlations were found between LF, HF, and NEUR_HI3. In EH-1 patients, all oscillatory rhythms influenced BP; this influence could be both negative (for MAYER_HI1, PULSE_HI2) and positive (for MAYER_HI2, RESP_HI3). In EH-2 patients, no relationship was found between blood pressure and oscillatory indices. Conclusion. The smaller number of factors influencing blood pressure and hemodynamics in the EH-2 group compared to the EH-1 group was more beneficial and favorable, which ensured faster and steadier normalization of blood pressure.


Author(s):  
Frank Schimmelfennig ◽  
Thomas Winzen ◽  
Tobias Lenz ◽  
Jofre Rocabert ◽  
Loriana Crasnic ◽  
...  

In this chapter, we provide statistical analyses of the establishment and empowerment of international parliamentary institutions (IPIs) in seventy-three relevant international organizations. We analyse whether IPI establishment was systematically associated with the conditions of parliamentarization and find robust and strong positive associations for general purpose and policy scope and robust but somewhat weaker positive correlations for diffusion. By contrast, neither authority nor democracy are systematically associated with the existence of IPIs. Governance failure is either insignificant or has a negative effect on IPI creation. Finally, we explore the correlation of the conditions of parliamentarization with IPI power and find a robust association of IPI authority with IPI legislative competencies.


2013 ◽  
Vol 23 (55) ◽  
pp. 225-233 ◽  
Author(s):  
Sandra Regina Kirchner Guimaraes

Starting with the alphabetic stage of writing acquisition, the learner struggles with issues related to spelling, including the segmentation of writing in graphic words. This study examined the conventional segmentation of words and its relation to morphosyntactic awareness in a sample of students in the 4th and 5th years of elementary education in public schools. Results reveal a discrepancy between the oral identification of words and performance in the segmentation of writing, with three criteria being used by students to define “word”: (1st) full meaning; (2nd) sequence of letters, not only one or two; (3rd) frequency of word use. Statistical analyses revealed significant positive correlations between conventional segmentation and morphosyntactic awareness. It is inferred that morphosyntactic skills support the establishment of the conventional notion of the word, and it is suggested that teachers promote the development of these skills, in order to ensure a greater command of the written language.


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