A Perth office worker who injured his neck when he became startled by a faulty alarm going off has successfully sued his employer for nearly $2 million in damages.

Michael Hooker was a computer draftsman at Allied Pumps in Welshpool when he suffered his injury in March 2012.

A device similar to the above personal gas detector startled Mr Hooker when triggered inside his office Credit:Frontline Safety UK

According to District Court of Western Australia court documents, Mr Hooker was sitting at his desk in an open-plan office about 2pm when another employee switched on a faulty personal gas detector, triggering a "loud and piercing screeching" alarm which startled Mr Hooker.

The 42-year-old reactively turned sharply to his left to identify the source of the noise, causing his knees to hit the side of his desk and send pain to his neck and shoulders.