Imagine having the ability to unleash the fullpower of acoustics with a radically newtechnology for detecting sounds! Imaginethe endless possibilities that this could bringwith an enhancement of studio-soundquality of music and sound recordings orthe improved-quality conversations wecould have through video calls or using oursmartphones.
To make this vision a reality, the PIONEARconsortium (Fig. 1) proposes the development of a novel photonic microphone technology that will allow for enhanced sound detection, from the faintest whisper to the loudest acoustic range imaginable! Microphones play an increasingly important role in how we communicate and perceive our everyday lives equipped with digital and virtual technologies. They have experienced a tremendous development leap in terms of significant size and cost reductions and are now ubiquitous in industrial and professional applications. Yet, despite all this progress, the current microphone technology falls short of receiving audio of the sensitivity limit such as that of the human ear. To date, the microphone has achieved a self-noise level of ≤0 decibels (dB). Sound Pressure Level(SPL), which corresponds to the threshold of human hearing, while also being capable of detecting sounds up to 130 dB SPL (the threshold of pain) and covering the full bandwidth of 20 kHz.
The main vision of the PIONEAR project is to design a high-resolution microphone with better-than-human-ear sound sensitivity. The PIONEAR microphone will be designed to have a similar form factor to the miniature MEMS microphones while aiming to outperform even much larger diaphragm microphones.
It will be enabled by a radically new sensing technology called ‘chromometry.’ Chromometric sensing refers to a method which uses light instead of electrical signals to detect sound. Such a sensing technique will allow to maximise sensor resolution and dynamic range of the PIONEAR microphone which could fundamentally revolutionise optical sensing by operating at low power while replacing expensive and power-consuming analogue-to-digital converters. The technology will encompass an innovative laser design for the conversion of changes in sound pressure that can be measured with remarkable resolution.
