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OtoRhinoLaryngology by Sfakianakis G.Alexandros Sfakianakis G.Alexandros,Anapafseos 5 Agios Nikolaos 72100 Crete Greece,tel : 00302841026182,00306932607174
An ongoing challenge exists in understanding and optimizing the acoustic droplet vaporization (ADV) process to enhance contrast agent effectiveness for biomedical applications. Acoustic signatures from vaporization events can be identified and differentiated from microbubble or tissue signals based on their frequency content. The present study exploited the wide bandwidth of a 128-element capacitive micromachined ultrasonic transducer (CMUT) array for activation (8 MHz) and real-time imaging (1 MHz) of ADV events from droplets circulating in a tube. Compared to a commercial piezoelectric probe, the CMUT array provides a substantial increase of the contrast-to-noise ratio.
The sound spectra obtained in a synthetic larynx exhibited subharmonic tones that are characteristic for diplophonia. Although the generation of subharmonics is commonly associated with asymmetrically oscillating vocal folds, the synthetic elastic vocal folds showed symmetrical oscillations. The amplitudes of the subharmonics decreased with an increasing lateral diameter of the supraglottal channel, which indicates a strong dependence of the supraglottal boundary conditions. Investigations of the supraglottal flow field revealed small cycle-to-cycle variations of the static pressure in the region of the pulsatile glottal jet as the origin of the first subharmonic tone. It is located at half the fundamental frequency of the vocal fold oscillation. A principle component analysis of the supraglottal flow field with the fully developed glottal jet revealed a large recirculation area in the second spatial eigenvector which deflected the glottal jet slightly in a perpendicular direction of the jet axis. The rotation direction of the recirculation area changed with different oscillation cycles between clockwise and counterclockwise. As both directions were uniformly distributed across all acquired oscillation cycles, a cycle-wise change can be assumed. It is concluded that acoustic subharmonics are generated by small fluctuations of the glottal jet location favored by small lateral diameters of the supraglottal channel.
This paper deals with nonporous windscreens used for reducing noise in infrasonic measurements. A model of sound transmission using a modal approach is derived. The system is a square plate coupled with a cavity. The model agrees with finite element simulations and measurements performed on two windscreens: a cubic windscreen using a material recommended by Shams, Zuckerwar, and Sealey [J. Acoust. Soc. Am. 118, 1335–1340 (2005)] and an optimized flat windscreen made out of aluminum. Only the latter was found to couple acoustical waves below 10 Hz without any attenuation. Moreover, wind noise reduction measurements show that nonporous windscreens perform similarly as a pipe array by averaging the pressure fluctuations. These results question the assumptions of Shams et al. and Zuckerwar [J. Acoust. Soc. Am. 127, 3327–3334 (2010)] about compact nonporous windscreens design and effectiveness.
The acoustic vector-sensor (a.k.a. the vector hydrophone) is a practical and versatile sound-measurement device, with applications in-room, open-air, or underwater. It consists of three identical uni-axial velocity-sensors in orthogonal orientations, plus a pressure-sensor—all in spatial collocation. Its far-field array manifold [Nehorai and Paldi (1994). IEEE Trans. Signal Process. 42, 2481–2491; Hawkes and Nehorai (2000). IEEE Trans. Signal Process. 48, 2981–2993] has been introduced into the technical field of signal processing about 2 decades ago, and many direction-finding algorithms have since been developed for this acoustic vector-sensor. The above array manifold is subsequently generalized for outside the far field in Wu, Wong, and Lau [(2010). IEEE Trans. Signal Process. 58, 3946–3951], but only if no reflection-boundary is to lie near the acoustic vector-sensor. As for the near-boundary array manifold for the general case of an emitter in the geometric near field, the far field, or anywhere in between—this paper derives and presents that array manifold in terms of signal-processing mathematics. Also derived here is the corresponding Cramér-Rao bound for azimuth-elevation-distance localization of an incident emitter, with the reflected wave shown to play a critical role on account of its constructive or destructive summation with the line-of-sight wave. The implications on source localization are explored, especially with respect to measurement model mismatch in maximum-likelihood direction finding and with regard to the spatial resolution between coexisting emitters.
A stochastic model is presented for nanoparticle transport in a biofilm to explain how the combination of acoustic oscillations and intermittent retention due to interaction with the pore walls of the biofilm leads to diffusion enhancement. An expression for the effective diffusion coefficient was derived that varies with the square of the oscillation velocity amplitude. This expression was validated by comparison of an analytical diffusion solution to the stochastic model prediction. The stochastic model was applied to an example problem associated with liposome penetration into a hydrogel, and it was found to yield solutions in which liposome concentration varied exponentially with distance into the biofilm.
Underwater sound of rigid-hulled inflatable boats was recorded 142 times in total, over 3 sites: 2 in southern British Columbia, Canada, and 1 off Western Australia. Underwater sound peaked between 70 and 400 Hz, exhibiting strong tones in this frequency range related to engine and propeller rotation. Sound propagation models were applied to compute monopole source levels, with the source assumed 1 m below the sea surface. Broadband source levels (10–48 000 Hz) increased from 134 to 171 dB re 1 μPa @ 1 m with speed from 3 to 16 m/s (10–56 km/h). Source power spectral density percentile levels and 1/3 octave band levels are given for use in predictive modeling of underwater sound of these boats as part of environmental impact assessments.
This study tested American preschoolers' ability to use phrasal prosody to constrain their syntactic analysis of locally ambiguous sentences containing noun/verb homophones (e.g., [The baby flies] [hide in the shadows] vs [The baby] [flies his kite], brackets indicate prosodic boundaries). The words following the homophone were masked, such that prosodic cues were the only disambiguating information. In an oral completion task, 4- to 5-year-olds successfully exploited the sentence's prosodic structure to assign the appropriate syntactic category to the target word, mirroring previous results in French (but challenging previous English-language results) and providing cross-linguistic evidence for the role of phrasal prosody in children's syntactic analysis.
The current investigation contributes to a perceptual similarity-based approach to dysarthria characterization by utilizing an innovative statistical approach, multinomial logistic regression with sparsity constraints, to identify acoustic features underlying each listener's impressions of speaker similarity. The data-driven approach also permitted an examination of the effect of clinical experience on listeners' impressions of similarity. Listeners, irrespective of level of clinical experience, were found to rely on similar acoustic features during the perceptual sorting task, known as free classification. Overall, the results support the continued advancement of a similarity-based approach to characterizing the communication disorders associated with dysarthria.
A stochastic model is presented for nanoparticle transport in a biofilm to explain how the combination of acoustic oscillations and intermittent retention due to interaction with the pore walls of the biofilm leads to diffusion enhancement. An expression for the effective diffusion coefficient was derived that varies with the square of the oscillation velocity amplitude. This expression was validated by comparison of an analytical diffusion solution to the stochastic model prediction. The stochastic model was applied to an example problem associated with liposome penetration into a hydrogel, and it was found to yield solutions in which liposome concentration varied exponentially with distance into the biofilm.
Underwater sound of rigid-hulled inflatable boats was recorded 142 times in total, over 3 sites: 2 in southern British Columbia, Canada, and 1 off Western Australia. Underwater sound peaked between 70 and 400 Hz, exhibiting strong tones in this frequency range related to engine and propeller rotation. Sound propagation models were applied to compute monopole source levels, with the source assumed 1 m below the sea surface. Broadband source levels (10–48 000 Hz) increased from 134 to 171 dB re 1 μPa @ 1 m with speed from 3 to 16 m/s (10–56 km/h). Source power spectral density percentile levels and 1/3 octave band levels are given for use in predictive modeling of underwater sound of these boats as part of environmental impact assessments.
This study tested American preschoolers' ability to use phrasal prosody to constrain their syntactic analysis of locally ambiguous sentences containing noun/verb homophones (e.g., [The baby flies] [hide in the shadows] vs [The baby] [flies his kite], brackets indicate prosodic boundaries). The words following the homophone were masked, such that prosodic cues were the only disambiguating information. In an oral completion task, 4- to 5-year-olds successfully exploited the sentence's prosodic structure to assign the appropriate syntactic category to the target word, mirroring previous results in French (but challenging previous English-language results) and providing cross-linguistic evidence for the role of phrasal prosody in children's syntactic analysis.
The current investigation contributes to a perceptual similarity-based approach to dysarthria characterization by utilizing an innovative statistical approach, multinomial logistic regression with sparsity constraints, to identify acoustic features underlying each listener's impressions of speaker similarity. The data-driven approach also permitted an examination of the effect of clinical experience on listeners' impressions of similarity. Listeners, irrespective of level of clinical experience, were found to rely on similar acoustic features during the perceptual sorting task, known as free classification. Overall, the results support the continued advancement of a similarity-based approach to characterizing the communication disorders associated with dysarthria.
Cochlear implantation: Optimizing outcomes through evidence-based clinical decisions.
Int J Audiol. 2016;55 Suppl 2:S1-2
Authors: Dowell R, Galvin K, Cowan R
PMID: 27329573 [PubMed - in process]
Audiology patient fall statistics and risk factors compared to non-audiology patients.
Int J Audiol. 2016 Jun 22;:1-7
Authors: Criter RE, Honaker JA
Abstract
OBJECTIVE: To compare fall statistics (e.g. incidence, prevalence), fall risks, and characteristics of patients who seek hearing healthcare from an audiologist to individuals who have not sought such services.
DESIGN: Case-control study.
STUDY SAMPLE: Two groups of community-dwelling older adult patients: 25 audiology patients aged 60 years or older (M age: 69.2 years, SD: 4.5, range: 61-77) and a control group (gender- and age-matched ±2 years) of 25 non-audiology patients (M age: 69.6, SD: 4.7, range: 60-77).
RESULTS: Annual incidence of falls (most recent 12 months) was higher in audiology patients (68.0%) than non-audiology patients (28.0%; p = .005). Audiology patients reported a higher incidence of multiple recent falls (p =.025) and more chronic health conditions (p = .028) than non-audiology patients.
CONCLUSIONS: Significantly more audiology patients fall on an annual basis than non-audiology patients, suggesting that falls are a pervasive issue in general hearing clinics. Further action on the part of healthcare professionals providing audiologic services may be necessary to identify individuals at risk for falling.
PMID: 27329486 [PubMed - as supplied by publisher]