The speakerphone quality of mobile phones could be set for a major improvement if a chip launched on 27 October 2010 by Scottish firm Wolfson Microelectronics takes off. The goal is to make telephone conferences using a mobile phone as the speakerphone acceptable for businesses but this should also benefit other users of portable devices.
The company is aiming its product at the smartphone market to enable high-definition audio in portable devices. Duncan Macadie, Wolfson’s product line manager for audio hubs, told the London pre-launch press conference on 26 October 2010 that he was also looking at applications in tablet computers, e-books and satnav devices. “It is easy to make a speaker louder,” he said, “but it is harder to make it clearer at the same time. Customers want the conference speakerphone quality to be the same on a handset. Generally, today phones are too quiet for this so there is a need to make them louder and clearer.”
The product Wolfson hopes will achieve this is the WM8958 Audio Hub, an integrated low-power codec for smartphones and other devices. The product is sampling now and the company expects to have final products early in 2011. “It will be the third quarter of 2011 before we expect to see products on the market using it,” said Macadie.
WM8958 Audio Hub
The three-channel audio hub provides 100dB signal-to-noise ratio during digital-to-analogue playback, while its integrated stereo class S/AB speaker driver and Class W headphone driver reduce power consumption during audio playback. It has an audio enhancement digital signal processor that runs a three-band compressor to produce the louder and clearer sound from small speakers without overloading them or otherwise damaging them.
Used with an on-board parametric equaliser and dynamic range controller, the compressor can boost and optimise speaker outputs to improve audio playback quality for multimedia applications and ringtones.
A smart digital microphone interface provides power regulation, a low jitter clock and decimation filters for up to four digital microphones. Active ground loop noise rejection and DC offset correction help stop pop noise and suppress ground noise on the headphone output.
Wolfson’s High-Definition Audio Vision
“One of the key things we are trying to implement is to have an audio experience that matches the high-definition video experience,” Macadie told the London press conference. “The audio playback experience is quite different today and we are trying to change that.”
Other work the company is doing is adding more comprehensive digital signal processing and audio processing capabilities to improve the ability of mobile phones to work in noisy environments. As a first step, the company also introduced two micro-electro-mechanical systems (MEMS) microphones for mobile phones, portable media players and similar applications. These are the company’s first digital microphones; it has produced analogue microphones in the past.
Steve Rogerson - Steve Rogerson is a UK-based writer specialising in television, technology, sports and beer.
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