In this paper we investigate the e®ects of microphone and speaker locations on the performance of active noise control in ducts. We study a so-called \symmetric" con ̄guration in which the collocated performance microphone/control speaker and the collocated measurement microphone/disturbance source pairs are located equidistance from the duct center. By applying an \alignment angle" analysis to ...

In this paper, we propose a dual-microphone target-directional speech enhancement system utilizing target-to-non-target directional signal ratio (TNR) based on dual-microphone phase differences in adverse noise environments. One of the important issues associated with multi-microphone speech enhancement methods is the effective utilization of spatial cues such as phase differences for target-sp...

In MEMS capacitive microphone design, it is very critical to get highest yielding rate and sensitivity as the two major factors dominate structure design of microphone. The centralpost MEMS microphone is introduced in this paper to differentiate from traditional fixed membrane boundary microphone since the construction is simple and only few masks are required in the process so that the yieldin...

A moving robot audio system contains a simple microphone or more precise microphone array as an audio sensor. One of the main functions of audio system in the mobile robots is to help them in speaker localization. There are many possibilities to choose the methods for processing of audio information from the corresponding audio robot sensors. The goal in this article is to propose and test the ...

A parabolic dish microphone is like a mirror telescope for sound. A parabolic reflector is used to collect and focus sound waves to a microphone receiver [1, 2]. The parabolic shape has the property that all sound waves impinging parallel to the central axis of the dish are reflected to its focus point. When the dish is aimed at a distant sound source it is safe to assume that all the sound wav...

Complement to standard E2611-09 of the American Society for Testing and Materials [Standard Test Method for Measurement of Normal Incidence Sound Transmission of Acoustical Materials Based on the Transfer Matrix Method (American Society for Testing and Materials, New York, 2009)] is proposed in order to measure normal incidence sound transmission loss of materials in a modified impedance tube u...

Coprime linear microphone arrays allow for narrower beams with fewer sensors. A coprime microphone array consists of two staggered uniform linear subarrays with M and N microphones, where M and N are coprime with each other. By applying spatial filtering to both subarrays and combining their outputs, M+N-1 microphones yield M⋅N directional bands. In this work, the coprime sampling theory is imp...

This paper investigates the use of microphone arrays in handsfree speaker recognition systems. Hands-free operation is preferable in many potential speaker recognition applications, however obtaining acceptable performance with a single distant microphone is problematic in real noise conditions. A possible solution to this problem is the use of microphone arrays, which have the capacity to enha...

Audio applications such as mobile communication and hearing aid devices demand a small size but high performance, stable and low cost microphone to reproduce a high quality sound. Capacitive microphone can be designed to fulfill such requirements with some trade-offs between sensitivity, operating frequency range, and noise level mainly due to the effect of device structure dimensions and visco...

We present an in-situ method for MEMS (microelectromechanical systems) microphone sensitivity optimization via the growth/retraction of nanoelectrodeposits to achieve high directionality in hearing aid applications. Using a DC bias at room temperature, nanoelectrodeposits are electrochemically deposited and dissolved on a Ag-doped Ge-Se solid electrolyte film on a microphone diaphragm. The grow...