Δευτέρα 9 Μαΐου 2016

Recovery of Vestibulo-Ocular Reflex Symmetry After an Acute Unilateral Peripheral Vestibular Deficit: Time Course and Correlation With Canal Paresis.

Background: We investigated how response asymmetries and deficit side response amplitudes for head accelerations used clinically to test the vestibular ocular reflex (VOR) are correlated with caloric canal paresis (CP) values. Methods: 30 patients were examined at onset of an acute unilateral peripheral vestibular deficit (aUPVD) and 3, 6, and 13 weeks later with three different VOR tests: caloric, rotating chair (ROT), and video head impulse tests (vHIT). Response changes over time were fitted with an exponential decay model and compared with using linear regression analysis. Results: Recovery times (to within 10% of steady state) were similar for vHIT-asymmetry and CP (>10 weeks) but shorter for ROT asymmetry (

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Best Masking Sound For Tinnitus

While tinnitus is an internal sound that doesn’t have a matching exterior source, sufferers can often find relief through external noise used to mask the sound constantly in their heads. Sound therapy is often used in conjunction with other therapies like neuromodulation and habituation.

Living with tinnitus often involves sound masking devices and applications that help dilute the sounds in the sufferer’s ear by providing background noise. While there might be certain white noise maskers that could work for some sufferers, not everyone will find relief from the same sounds. Sufferers do not report the same type of high-pitched sound. From one person to the next, the sound could be completely different. Some people hear a constant, low hissing while others hear a loud whine.

The best masking sound for tinnitus has to provide relief from the frequency of the tinnitus sound, which can often mean a custom created sound. AudioNotch has a free library of masking sounds that can be used to provide relief.

The best masking sound for tinnitus can be downloaded as an mp3 to be played anytime you need relief. The noises can be kept on the website to be used at any time. They can be converted to be used as sound therapy with AudioNotch too. The sound library has pink, brown and white noise as well as nature sounds like one called beach surf, which sounds like the ocean ebbing and flowing gently. There’s also the sound of water running in a variety of methods from kitchen sink to mountain stream to waterfall.

Variety of Sounds:

  • Pink Noise
  • Brown Noise
  • White Noise
  • Autumn Wind
  • Beach Surf
  • City Sweeper
  • Heavy Rain
  • Kitchen Sink
  • Mountain Stream
  • Summer Night
  • Waterfall
  • Waterfall #2
  • White Noise with no High Frequencies
  • Kitchen Sink with no High Frequencies

The best masking sound for tinnitus will vary from one individual to the next, which is why there are so many different masking sounds in the library. Each sound in the library plays between five and ten minutes, but they can be set to repeat continuously. There’s also the option to shuffle the sounds to provide relief.

The library of sounds gives the sufferer many options for masking tinnitus without having to spend thousands on hearing aids and medical-grade sound therapy.




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The acute physiological stress response to an emergency alarm and mobilization during the day and at night

Sarah J Hall, Brad Aisbett, Jamie L Tait, Anne I Turner, Sally A Ferguson, Luana C Main

Noise and Health 2016 18(82):150-156

The purpose of this study was to investigate the acute physiological stress response to an emergency alarm and mobilization during the day and at night. Sixteen healthy males aged 25 ± 4 years (mean ± SD) spent four consecutive days and nights in a sleep laboratory. This research used a within-participants design with repeated measures for time, alarm condition (alarm or control), and trial (day or night). When an alarm sounded, participants were required to mobilize immediately. Saliva samples for cortisol analysis were collected 0 min, 15 min, 30 min, 45 min, 60 min, 90 min, and 120 min after mobilization, and at corresponding times in control conditions. Heart rate was measured continuously throughout the study. Heart rate was higher in the day (F20,442 = 9.140, P < 0.001) and night (F23,459 = 8.356, P < 0.001) alarm conditions compared to the respective control conditions. There was no difference in saliva cortisol between day alarm and day control conditions. Cortisol was higher (F6,183 = 2.450, P < 0.001) following the night alarm and mobilization compared to the night control condition. The magnitude of difference in cortisol between night control and night alarm conditions was greater (F6,174 = 4.071, P < 0.001) than the magnitude of difference between the day control and day alarm conditions. The augmented heart rate response to the day and night alarms supports previous observations in field settings. Variations in the cortisol responses between conditions across the day and night may relate to differences in participants' ability to interpret the alarm when sleeping versus when awake.

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Exposures to road traffic, noise, and air pollution as risk factors for type 2 diabetes: A feasibility study in Bulgaria

Angel M Dzhambov, Donka D Dimitrova

Noise and Health 2016 18(82):133-142

Type 2 diabetes mellitus (T2DM) is a growing public health problem in Bulgaria. While individual and lifestyle determinants have been researched; till date there has been no study on environmental risks such as road traffic, noise, and air pollution. As a first step toward designing a large-scale population-based survey, we aimed at exploring the overall associations of prevalent T2DM with exposures to road traffic, noise, and air pollution. A total of 513 residents of Plovdiv city, Bulgaria were recruited. Individual data on self-reported doctor-diagnosed T2DM and confounding factors were linked to objective and self-rated exposure indicators. Logistic and log-link Poisson regressions were conducted. In the fully adjusted logistic models, T2DM was positively associated with exposures to L den 71-80 dB (odds ratio (OR) = 4.49, 95% confidence interval (CI): 1.38, 14.68), fine particulate matter (PM) 2.5 25.0-66.8 μg/m 3 (OR = 1.32, 95% CI: 0.28, 6.24), benzo alpha pyrene 6.0-14.02 ng/m 3 (OR = 1.76, 95% CI: 0.52, 5.98) and high road traffic (OR = 1.40, 95% CI: 0.48, 4.07). L den remained a significant risk factor in the: Poisson regression model. Other covariates with consistently high multivariate effects were age, gender, body mass index, family history of T2DM, subjective sleep disturbance, and especially bedroom location. We concluded that residential noise exposure might be associated with elevated risk of prevalent T2DM. The inferences made by this research and the lessons learned from its limitations could guide the designing of a longitudinal epidemiological survey in Bulgaria.

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Moderators of noise-induced cognitive change in healthy adults

Bernice AL Wright, Emmanuelle R Peters, Ulrich Ettinger, Elizabeth Kuipers, Veena Kumari

Noise and Health 2016 18(82):117-132

Environmental noise causes cognitive impairment, particularly in executive function and episodic memory domains, in healthy populations. However, the possible moderating influences on this relationship are less clear. This study assessed 54 healthy participants (24 men) on a cognitive battery (measuring psychomotor speed, attention, executive function, working memory, and verbal learning and memory) under three (quiet, urban, and social) noise conditions. IQ, subjective noise sensitivity, sleep, personality, paranoia, depression, anxiety, stress, and schizotypy were assessed on a single occasion. We found significantly slower psychomotor speed (urban), reduced working memory and episodic memory (urban and social), and more cautious decision-making (executive function, urban) under noise conditions. There was no effect of sex. Variance in urban noise-induced changes in psychomotor speed, attention, Trail Making B-A (executive function), and immediate recall and social noise-induced changes in verbal fluency (executive function) and immediate recall were explained by a combination of baseline cognition and paranoia, noise sensitivity, sleep, or cognitive disorganization. Higher baseline cognition (but not IQ) predicted greater impairment under urban and social noise for most cognitive variables. Paranoia predicted psychomotor speed, attention, and executive function impairment. Subjective noise sensitivity predicted executive function and memory impairment. Poor sleep quality predicted less memory impairment. Finally, lower levels of cognitive disorganization predicted slower psychomotor speed and greater memory impairment. The identified moderators should be considered in studies aiming to reduce the detrimental effects of occupational and residential noise. These results highlight the importance of studying noise effects in clinical populations characterized by high levels of the paranoia, sleep disturbances, noise sensitivity, and cognitive disorganization.

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Lack of contralateral suppression in transient-evoked otoacoustic emissions in multiple chemical sensitivity: a clinical correlation study

Alessandro Micarelli, Andrea Viziano, Giuseppe Genovesi, Ernesto Bruno, Fabrizio Ottaviani, Marco Alessandrini

Noise and Health 2016 18(82):143-149

Multiple chemical sensitivity (MCS) is a chronic disorder characterized by a variety of symptoms associated with the exposure to chemicals at a concentration below the toxic level. Previous studies have demonstrated peculiar responses in brain activity in these patients with respect to sensory stimuli while the association between chemical sensitivity and other environmental intolerances such as noise sensitivity has been questioned by researchers. In this study, a cohort of 18 MCS patients underwent transient-evoked otoacoustic emission (TEOAE) testing with and without contralateral suppression to evaluate the functionality of the medial olivocochlear (MOC) reflex involved in speech-in-noise sensitivity. Results were compared with an age- and gender-matched control group (n = 20) and correlation analysis with disease onset and quick environmental exposure sensitivity inventory (qEESI) symptom severity scale was performed. Subjects affected by MCS showed statistically significant impairment of MOC reflex, and the onset of the disease and several symptom subscales showed to be correlated to such reduction in some of the frequencies tested. These data suggest that alterations of MOC reflex could be part of the complex features of this disease although more studies are needed to further explore auditory perception disorders in environmental intolerances.

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Hearing loss in the Royal Norwegian Navy: A longitudinal study

Kaja Irgens-Hansen, Valborg Baste, Magne Bratveit, Ola Lind, Vilhelm F Koefoed, Bente E Moen

Noise and Health 2016 18(82):157-165

The aims of this longitudinal study were to investigate a significant threshold shift (STS) among personnel working on board the Royal Norwegian Navy's (RNoN) vessels between 2012 and 2014 and to identify possible determinants of STS. Hearing thresholds were measured by pure tone audiometry in two consecutive examinations (n = 226). STS was defined as an average change in hearing thresholds ≥ + 10 dB at 2,000 Hz, 3,000 Hz, and 4,000 Hz in either ear. Determinants of STS were assessed through a questionnaire. The incidence of STS was 23.0%. Significant determinants of STS were the number of episodes of temporary threshold shifts (TTS) in the Navy, exposure to continuous loud noise during work on board, and the number of gun shots (in the Navy, hunting, and sports). This study indicated a significant association between noise exposure on board Navy vessels and development of STS.

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Automatic grunt detector and recognizer for Atlantic cod (Gadus morhua)

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Northwest Atlantic cod (Gadus morhua) have been heavily overfished in recent years and have not yet recovered. Passive acoustic technology offers a new approach to identify the spatial location of spawning fish, as well as their seasonal and long term persistence in an area. To date, the lack of a species-specific detector has made searching for Atlantic cod grunts in large amounts of passive acoustic data cumbersome. To address this problem, an automatic grunt detection and recognition algorithm that processes yearlong passive acoustic data recordings was designed. The proposed technique is a two-stage hypothesis testing algorithm that includes detecting and recognizing all grunt-like sounds. Test results demonstrated that the algorithm provided a detection probability of 0.93 for grunts with a signal-to-noise ratio (SNR) higher than 10 dB, and a detection probability of 0.8 for grunts with the SNR ranging from 3 to 10 dB. This detector is being used to identify cod in current and historical data from U.S. waters. Its use has significantly reduced the time required to find and validate the presence of cod grunts.



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Compensation for a lip-tube perturbation in 4-year-olds: Articulatory, acoustic, and perceptual data analyzed in comparison with adults

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The nature of the speech goal in children was investigated in a study of compensation strategies for a lip-tube perturbation. Acoustic, articulatory, and perceptual analyses of the vowels /y/ and /u/ produced by ten 4-year-old French speakers and ten adult French speakers were conducted under two conditions: normal and with a large tube inserted between the lips. Ultrasound and acoustic recordings of isolated vowels were made in the normal condition before any perturbation, for each of the trials in the perturbed condition, and in the normal condition after the perturbed trials. Data revealed that adult participants moved their tongues in the perturbed condition more than children did. The perturbation was generally at least partly compensated for during the perturbed trials in adults, but children did not show a typical learning effect. In particular, unsystematic improvements were observed during the sequence of perturbed trials, and after-effects were not clear in the articulatory domain. This suggests that children may establish associative links between multisensory phonemic representations and articulatory maneuvers, but those links may mainly rely on trial-to-trial, error-based feedback correction mechanisms rather than on the internal model of the speech production apparatus, as they are in adults.



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Quantitative analysis of a frequency-domain nonlinearity indicator

In this paper, quantitative understanding of a frequency-domain nonlinearity indicator is developed. The indicator is derived from an ensemble-averaged, frequency-domain version of the generalized Burgers equation, which can be rearranged in order to directly compare the effects of nonlinearity, absorption, and geometric spreading on the pressurespectrum level with frequency and distance. The nonlinear effect is calculated using pressure-squared-pressure quadspectrum. Further theoretical development has given an expression for the role of the normalized quadspectrum, referred to as Q/S by Morfey and Howell [AIAA J. 19, 986–992 (1981)], in the spatial rate of change of the pressurespectrum level. To explore this finding, an investigation of the change in level for initial sinusoids propagating as plane waves through inviscid and thermoviscous media has been conducted. The decibel change with distance, calculated through Q/S, captures the growth and decay of the harmonics and indicates that the most significant changes in level occur prior to sawtooth formation. At large distances, the inviscid case results in a spatial rate of change that is uniform across all harmonics. For thermoviscous media, large positive nonlinear gains are observed but offset by absorption, which leads to a greater overall negative spatial rate of change for higher harmonics.



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Influence of voxelization on finite difference time domain simulations of head-related transfer functions

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The scattering around the human pinna that is captured by the Head-Related Transfer Functions (HRTFs) is a complex problem that creates uncertainties in both acoustical measurements and simulations. Within the simulation framework of Finite Difference Time Domain(FDTD) with axis-aligned staircase boundaries resulting from a voxelization process, the voxelization-based uncertainty propagating in the HRTF-captured sound field is quantified for one solid and two surface voxelization algorithms. Simulated results utilizing a laser-scanned mesh of Knowles Electronics Manikin for Acoustic Research (KEMAR) show that in the context of complex geometries with local topology comparable to grid spacing such as the human pinna, the voxelization-related uncertainties in simulations emerge at lower frequencies than the generally used accuracy bandwidths. Numerical simulations show that the voxelization process induces both random error and algorithm-dependent bias in the simulated HRTF spectral features. Frequencies fr below which the random error is bounded by various dB thresholds are estimated and predicted. Particular shortcomings of the used voxelization algorithms are identified and the influence of the surface impedance on the induced errors is studied. Simulations are also validated against measurements.



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Durations required to distinguish noise and tone: Effects of noise bandwidth and frequencya)

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Perceptual audio coders exploit the masking properties of the human auditory system to reduce the bit rate in audio recording and transmission systems; it is intended that the quantization noise is just masked by the audio signal. The effectiveness of the audio signal as a masker depends on whether it is tone-like or noise-like. The determination of this, both physically and perceptually, depends on the duration of the stimuli. To gather information that might improve the efficiency of perceptual coders, the duration required to distinguish between a narrowband noise and a tone was measured as a function of center frequency and noise bandwidth. In experiment 1, duration thresholds were measured for isolated noise and tone bursts. In experiment 2, duration thresholds were measured for tone and noise segments embedded within longer tone pulses. In both experiments, center frequencies were 345, 754, 1456, and 2658 Hz and bandwidths were 0.25, 0.5, and 1 times the equivalent rectangular bandwidth of the auditory filter at each center frequency. The duration thresholds decreased with increasing bandwidth and with increasing center frequency up to 1456 Hz. It is argued that the duration thresholds depended mainly on the detection of amplitude fluctuations in the noise bursts.



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