Vocal singing skills by cochlear implanted children without formal musical training: Familiar versus unfamiliar songs.

OBJECTIVES: Vocal singing skills in pediatric CI users are not much known due to the limited number of studies. The principal aim of the present study was to evaluate vocal singing skills in Italian pediatric CI users. A further aim was to investigate factors that may significantly influence their performance. METHODS: The participants were twenty-two implanted children and twenty-two hearing peers. Their vocal singing skills for familiar ("Happy Birthday to You") and unfamiliar songs ("Baton Twirler" from Pam Pam 2- Tribute to Gordon) were evaluated in relation to their music perception (the Gordon test). Acoustic analysis was performed using Praat and MATLAB software. Nonparametric statistical tests and principal component analysis (PCA) were used to analyze the data. RESULTS: Hearing children outperformed implanted peers in both music perception and vocal singing tasks (all measures regarding intonation, vocal range, melody, and memory for the familiar song versus measures regarding intonation and overall melody production for the unfamiliar song). Music perception and vocal singing performances revealed strong correlations. For the familiar and unfamiliar songs, age-appropriate vocal singing was observed in 27.3% versus 45.4% of children, all implanted within 24 months of age. Age at implantation and duration of CI experience were moderately correlated with the total score obtained from the Gordon test. CONCLUSION: Implanted children show limited vocal singing skills in comparison to their hearing peers. However, some children implanted within 24 months of age seem to achieve vocal singing skills as good as their hearing peers. Future research could be useful to better understand the role of brain plasticity to implement specific training programs for both music perception and vocal singing.

Stabilization of a p-u Sensor Mounted on a Vehicle for Measuring the Acoustic Impedance of Road Surfaces.

The knowledge of the acoustic impedance of a material allows for the calculation of its acoustic absorption. Impedance can also be linked to structural and physical proprieties of materials. However, while the impedance of pavement samples in laboratory conditions can usually be measured with high accuracy using devices such as the impedance tube, complete in-situ evaluation results are less accurate than the laboratory results and is so time consuming that a full scale implementation of in-situ evaluations is practically impossible. Such a system could provide information on the homogeneity and the correct laying of an installation, which is proven to be directly linked to its acoustic emission properties. The present work studies the development of a measurement instrument which can be fastened through holding elements to a moving laboratory (i.e., a vehicle). This device overcomes the issues that afflict traditional in-situ measurements, such as the impossibility to perform a continuous spatial characterization of a given pavement in order to yield a direct evaluation of the surface's quality. The instrumentation has been uncoupled from the vehicle's frame with a system including a Proportional Integral Derivative (PID) controller, studied to maintain the system at a fixed distance from the ground and to reduce damping. The stabilization of this device and the measurement system itself are evaluated and compared to the traditional one.

Lamb waves propagation along 3C-SiC/AlN membranes for application in temperature-compensated, high-sensitivity gravimetric sensors.

The propagation of the fundamental quasi-symmetric Lamb mode S(0) travelling along 3C-SiC/c-AlN composite plates is theoretically studied with respect to the AlN and SiC film thickness, the acoustic wave propagation direction and the electrical boundary conditions. The temperature effects on the phase velocity have been considered for four AlN/SiC-based electroacoustic coupling configurations, specifically addressing the design of temperature-compensated, enhanced-coupling, GHz-range electroacoustic devices. The gravimetric sensitivity and resolution of the four temperature-stable SiC/AlN composite structures are theoretically investigated with respect to both the AlN and SiC sensing surface. The SiC/AlN-based sensor performances are compared to those of surface acoustic waves and Lamb S(0) mode mass sensors implemented on bulk conventional piezoelectric materials and on thin suspended membranes.