Search results for "ACOUSTIC"
showing 10 items of 1590 documents
Children's brain responses to sound changes in pseudo words in a multifeature paradigm.
2011
Abstract Objective The multifeature mismatch negativity (MMN) paradigm has previously been used to study MMN responses to changes in tones or isolated syllables. We tested 4–12year old children's MMNs to changes in a naturally produced pseudo word context. Methods We studied preschoolers' (under the age of 7years, N =15, mean age 5years 4months) and school childrens' (over the age of 7years, N =15, mean age 9years 3months) MMNs to five types of changes (vowel duration, fundamental frequency, gap, intensity, vowel identity) in the middle syllable of a pseudo word [tɑtɑtɑ] using a multifeature paradigm. Results Vowel duration and gap changes elicited larger frontocentral MMN responses than ot…
Event-related potentials in newborns with and without familial risk for dyslexia: principal component analysis reveals differences between the groups
2003
Differences revealed by factor scores extracted by principal component analysis (PCA) from event-related potential (ERP) data of newborns with and without familial risk for dyslexia were examined and compared to results obtained by using original averaged ERPs. ERPs to consonant-vowel syllables (synthetic /ba/, /da/, /ga/; and natural /paa/, /taa/, /kaa/) were recorded from 26 at-risk and 23 control 1-7 day-old infants. The stimuli were presented equiprobably and with interstimulus intervals varying at random from 3,910 to 7,285 ms. Statistically significant between-group differences were found to be relatively similar irrespective of the methods of analysis (original ERPs vs. factor scores…
Heart rate turbulence for guiding electric therapy in patients with cardiac failure
2009
It is well-known that a reduction of the cardiac frequency variability, measurable with the Heart Rate Variability (HRV) system, is an indirect expression of the sympathetic-autonomic tone. Another index, Heart Rate Turbulence (HRT), has been recently suggested as a possible unit of measurement for the sympathetic-autonomic tone: this system allows to estimate the baro-reflex response of the carotid arteries to an early ventricular extra-systole by analysing heart rate variations induced by a premature beat.In our research we have analyzed this phenomenon in patients affected by moderate or severe cardiac failure. In particular, we divided 110 patients into two arms: subjects with or withou…
Effects of sulpiride on the orienting movement evoked By acoustic stimulation in the Rat.
2000
Abstract Drugs that selectively block D 2 receptors are known to provoke a rapid cell firing increase followed by A9 and A10 dopaminergic (DA) neuron inactivation (depolarization block). In this study, possible relationships between cell firing rapid increase and specific behavioral effects, linked to sensorimotor integration, were investigated in the rat. To this purpose, with the aid of a video camera apparatus and a frame-by-frame analysis, effects of sulpiride-induced blockade of DA D 2 receptors were analyzed on the orienting movement of the head induced by acoustic stimulation. In a control group of rats, during trials lasting 20 min, latency and duration of head turning (HT) were 186…
Auditory Neuropathy in Children
2001
Auditory neuropathy is a sensorineural disorder characterized by absent or abnormal auditory brainstem evoked potentials and normal cochlear outer hair cell function. A variety of processes is thought to be involved in its pathophysiology and their influence on hearing may be different. We present here the diagnostic sequence and management of two new cases of auditory neuropathy in breastfeeding children.
An experimental comparative study of dexamethasone, melatonin and tacrolimus in noise-induced hearing loss.
2008
The calcineurin inhibitor tacrolimus (TCR) and the pineal gland hormone and antioxidant melatonin (MLT) have been shown to possess otoprotective properties against noise-induced hearing loss (NIHL). In contrast, dexamethasone (DXM) was not effective as an otoprotective agent against NIHL. Further studies are needed to understand the exact molecular mechanisms involved.Exposure to noise pollution and use of audio devices for long periods of time at high volume is known to cause hearing loss or NIHL. Our goal was to evaluate the effectiveness of various known compounds such as the anti-inflammatory DXM, the antioxidant MLT and the immunosuppressant TCR against NIHL.Thirty-two Wistar rats were…
First Experiences With the Ponto⢢ SuperPower Osseointegrated Device
2018
Osseointegrated hearing devices Power and SuperPower present indications for bone thresholds of 55 and 65 dB respectively. We conducted a prospective observational study of a series of six cases with mixed hearing loss for whom implantation of the DAO Ponto™ Super-Power was performed. Tonal and verbal evaluations without and with background noise (HINTS) were performed prior to implantation and six months after adaptation. All the participants showed improvement in tonal and verbal results, varying according to the degree of contralateral hearing loss. The verbal results with background noise were noteworthy, where most of the patients obtained a signal-to-noise ratio between 2 and 4 dB. Th…
Diagnostic subgroups of developmental dyslexia have different deficits in neural processing of tones and phonemes.
2004
The present study addressed auditory processing in 8-11-year-old children with developmental dyslexia by means of event-related brain potentials (ERP). Cortical sound reception was evaluated by recording N250 responses to syllables and tones and cortical sound discrimination by analyzing the mismatch negativity (MMN) to syllable and tone changes. We found that both cortical sound reception and sound discrimination were impaired in dyslexic children. The analysis of the data obtained from two dyslexic subgroups, Dyslexics-1 being impaired in non-word reading (or both non-word and frequent word reading) and Dyslexics-2 in frequent word reading but not in non-word reading, revealed that the MM…
Maturational effects on newborn ERPs measured in the mismatch negativity paradigm.
2003
Abstract The mismatch negativity (MMN) component of event-related potentials (ERPs), a measure of passive change detection, is suggested to develop early in comparison to other ERP components, and an MMN-like response has been measured even from preterm infants. The MMN response in adults is negative in polarity at about 150–200 ms. However, the response measured in a typical MMN paradigm can also be markedly different in newborns, even opposite in polarity. This has been suggested to be related to maturational factors. To verify that suggestion, we measured ERPs of 21 newborns during quiet sleep to rarely occurring deviant tones of 1100 Hz (probability 12%) embedded among repeated standard…
Prelingual sensorineural hearing loss and infants at risk: Western Sicily report.
2013
Objective: To evaluate independent etiologic factor associated with sensorineural hearing loss (SNHL) in newborn at risk; to study the role of their interaction especially in NICU infants who present often multiple risk factors for SNHL. Methods: The main risk factors for SNHL reported by JCIH 2007 were evaluated on 508 infant at risk ranging from 4 to 20 weeks of life, transferred to the Audiology Department of Palermo from the main births centers of Western Sicily. After a global audiological assessment, performed with TEOAE, tympanometry and ABR, the prevalence and the effect of risk factors was statistically studied through univariate and multivariate analysis on the total population (n…