Weakly electric fish emit an AC electric field into the water and use thousands of sensors on the skin to detect field perturbations due to surrounding objects. The fish's active electrosensory system allows them to navigate and hunt, using separate neural pathways and receptors for resistive and capacitive perturbations. We have previously developed a sensing method inspired by the weakly elec...

In this paper, we introduce a noise robust speech recognition system for a voice-driven wheelchair. Our system has adopted a microphone array system in order for the user not to need to wear a microphone. By mounting the microphone array system on the wheelchair, our system can easily distinguish the user’s utterances from other voices without using a speaker identification technique. We have a...

The present work aims to develop ultra-wide bandwidth air-coupled capacitive micromachined ultrasonic transducers (CMUTs) for binary gas mixture analysis. detection principle is based on time-of-flight (ToF) measurements, in order monitor ultrasound velocity variations. To perform such CMUTs were especially designed out of resonance mode, like a microphone. chosen membrane size 32 × µm2 and gap...

Capacitive input devices are becoming increasingly prevalent in consumer devices. This paper presents the hardware and algorithms for the low cost implementation of a capacitive 2.5D input device. The low cost and low power consumption of the device make it suitable for use in portable devices such as cellular phones. The electrical properties used are such that the preexisting snap dome techno...

Multi-microphone speech enhancement methods typically require a reference position with respect to which the target signal is estimated. Often, this arbitrarily chosen as one of microphones. However, it has been shown that choice microphone can have significant impact on final noise reduction performance. In paper, we therefore theoretically analyze selecting performance near-end being taken in...

OF DOCTORAL DISSERTATION AALTO UNIVERSITY SCHOOL OF SCIENCE AND TECHNOLOGY P.O. BOX 11000, FI-00076 AALTO http://www.aalto.fi Author Matti Paavola Name of the dissertation Manuscript submitted May 24, 2010 Manuscript revised August 24, 2010 Date of the defence October 1, 2010 Article dissertation (summary + original articles) Monograph Faculty Department Field of research Opponent(s) Supervisor...

Wireless Fidelity (WiFi) and Wireless microphone are assumed to operate on adjacent channels in TV White Spaces(TVWS). The Scenario of WiFi potentially interfering with Wireless microphone is analyzed through Minimum Coupling Loss (MCL) and Spectrum Engineering Advanced Monte Carlo Analysis Tool (SEAMCAT) based on the Monte-Carlo simulation method. In the case of single WiFi interfering with Wi...

This study explored the use patterns and benefits of directional microphone technology in real-world situations experienced by patients who had been fitted with switchable omnidirectional/directional hearing aids. Telephone interviews and paper-and-pencil questionnaires were used to assess perceived performance with each microphone type in a variety of listening situations. Patients who used th...

There has been a strong interest in theory and design of spherical microphone arrays in recent years due to their possible use in recording directional sounds for surround sound creation. The theory of such arrays is based on decomposition of sound fields to spherical harmonics which are the natural basis functions for valid sound fields over three dimensional space. However, due to physical si...