We analyze the capacity of single-input-multi-output (SIMO) acoustic channels with long propagation delays and longterm frequency-dependent properties that are found in acoustic channels. The focus of this paper is on the effects of feedback delay on the achievable rate of the acoustic channel. Four power allocation policies are analyzed within a framework of orthogonal frequency division multi...

BACKGROUND New and improved methods of feedback suppression are routinely introduced in hearing aids; however, comparisons of additional gain before feedback (AGBF) values across instruments are complicated by potential variability across subjects and measurement methods. PURPOSE To examine the variability in AGBF values across individual listeners and an acoustic manikin. RESEARCH DESIGN A...

In this paper, a numerical study is presented to investigate a boundary-layer instability on the suction side of a NACA0006 airfoil, induced by aerodynamic sound scattered from a trailingedge. By incorporating a linear stability analysis into the direct simulations with a compressible Navier-Stokes code using high-order accurate schemes, the unsteady characteristics are estimated upon resolving...

Like human speech, vocal behavior in songbirds depends critically on auditory feedback. In both humans and songbirds, vocal skills are acquired by a process of imitation whereby current vocal production is compared to an acoustic target. Similarly, performance in adulthood relies strongly on auditory feedback, and online manipulations of auditory signals can dramatically alter acoustic producti...

Prior active room reverberation enhancement systems have typically employed microphones, artificial reverberator filters, and loudspeakers to change the reverberant properties of a room. However, acoustic feedback from the loudspeakers to the microphones has had the potential to drive such systems unstable. To avoid feedback instabilities, we apply passivity techniques from control theory to de...

Many species of bat emit acoustic signals and use information carried by echoes reflecting from nearby objects to navigate and forage. It is widely documented that echolocating bats adjust the features of sonar calls in response to echo feedback; however, it remains unknown whether audiovocal feedback contributes to sonar call design. Audiovocal feedback refers to the monitoring of one's own vo...

We have developed a system that breaks input speech into segments using an acoustic similarity measure. The aim is to detect the time points where the acoustic characteristics change, usually due to speaker changes but also resulting from changes in the acoustic environment. We have also developed a system to cluster the segments generated by the first system into clusters composed of homogeneo...

We discuss herein recent experimental and numerical studies examining resonant flow-acoustic feedback–loop interactions in transitional airfoils (i.e., possessing a notable area of laminar-to-turbulent boundary-layer transition) characteristic low-to-medium Reynolds number flow regimes. Such are commonly attributed to the viscous dynamics convected structures scattering into acoustic waves at t...