Audience Technology – Noise Suppression on iPhone 5

iPhone 5 Noise Suppression Technology

In what can only be described as a curious move, Audience, creators of noise supression chip technology, has announced that it appears unlikely the company’s technology will be used in the upcoming iphone 5. The earSmart technology is currently used in the iPhone 4S to reduce background noise. Noise suppression, serves to improve ingoing and outgoing call quality and also improves voice recognition for Siri’s performance.

Why use noise suppression and how does it work?

In the context of Siri, for voice recognition to function the DSP must be able to differentiate between the target signal (user’s voice) and any spurious noise. If the dynamic range is not great enough the processor may ‘confuse’ the noise as target signal and attempt to apply the voice recognition algorithm to it rather than the intended signal.

Ambient or Background Noise

Examples of noise competing with the target signal include traffic, other nearby conversations, plant or air conditioning, radio, tv, wind etc. These sounds can be lumped together and referred to as environmental, ambient or simple background noise. This type of background noise differs from the traditional definition of background noise which describes noise – digital processor, thermal or mechanical, created by components within electronic devices.

Applications of Noise Suppression and Noise Reduction

Background noise reduction technology has many applications including mobile phones, forensic audio, audio restoration and post production. There are various ways to implement noise reduction, most involving techniques such as multiband gating and equalisation (can be performed dynamically), psychoacoustics and profiling.

Noise Reduction Vs noise Suppression

Though the desired effect of noise suppression and noise reduction is the same, the application differs slightly. Noise suppression in cell phones differs from noise reduction in recorded program material in that it aims to prevent background noise from entering the stream in the first instance and is processed live, or in ‘real time’. Noise reduction on the other hand typically aims to remove noise from a pre recorded signal and as such noise reduction can utilise some techniques that noise suppression can’t use on the fly.

New Noise Suppression Technology on iPhone 5?

Back to the iphone 5 and Audience’s announcement. It seems that Apple has found an alternative solution solution for its Siri noise suppression requirements, possibly developed in house. The speculation is that a cheaper or easier to implement technology will be used. Some Apple critics are claiming that Apple has simply bought the rights to lock up the IP. Did apple intend ever to use the Audience IP longterm? Probably.

I’ll be wrapping up on any audio improvements in the iPhone when it’s released, so be sure to check back and get the latest news on what’s changed audio wise in iPhone 5 with iOS6.

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