The University of Southampton
Engineering and the Environment

Research project: Generating a Personal Listening Zone from a Mobile Device

Currently Active: 
Yes

Mobile audio devices are widely used in public spaces and reducing the noise nuisance that they pose can be achieved using loudspeaker arrays.

Project Overview

Personal audio system geometry
Personal audio system geometry

Mobile devices such as mobile phones, tablet computers, portable games consoles and laptops use loudspeakers to allow the user to hear the audio output of the device whilst it is held at a distance. The use of such devices in public spaces raises an issue of user privacy and is a noise nuisance to those nearby. This motivates the need for a personal audio system in which the sound is focused towards the user of the device and this can be achieved using an array of loudspeakers.

In this project, which was in part supported by a Research and Development Project for Samsung, different loudspeaker array configurations have been investigated for a mobile phone sized device, as shown in the photo. In general, the use of a large number of loudspeakers provides the best performance in terms of generating a listening, or bright zone for the device user. However, the use of large numbers of loudspeakers is impractical due to cost and weight limitations, and such arrays have also been shown to be more susceptible to the variations that are inherent in large scale manufacturing.

Measured directivity of two loudspeaker mobile phone system
Measured directivity

A practical system has been proposed which employs two loudspeakers on the mobile phone. The effects of the mobile phone body on the performance of this system have been investigated in terms of both the acoustic performance and the electrical power requirement. At low frequencies it has been shown that the mobile phone body reduces the electrical power required by the loudspeaker array, which is a clear advantage in a mobile device. At high frequencies the mobile phone body limits the performance that can be achieved using the loudspeaker array, however, by careful design of the individual loudspeakers it is possible to maintain a personal listening zone through the inherent high frequency directivity of loudspeakers.

Mobile phone mock-up with embedded loudspeakers.
Mobile phone mock-up

Associated research themes

Acoustics

Mechatronics

Signal Processing and Control

Related research groups

Signal Processing and Control Group

Publications

Staff

Share this research project Facebook Google+ Twitter Weibo

We use cookies to ensure that we give you the best experience on our website. If you continue without changing your settings, we will assume that you are happy to receive cookies on the University of Southampton website.

×