This project explored noise in control rooms and detection of alarms. The findings informed a follow-on project that resulted in the design of new, human-factored alarm sounds for operator consoles.
Auditory alarm use in control rooms across COP membership was investigated using a combination of site visits, a survey, and the application of evidence-based research and best practice. A novel, comprehensive and future-proof approach to auditory alarm implementation was developed for the COP in the form of an Auditory Mapping Protocol (AMP).
All environments where alarms are used are governed by two key elements: what event is making the sound, and the urgency of the situation being signalled. Typically there will some interdependency of these factors. This will be true of control rooms, with the additional requirement/request that information on which console is signalling the alarm (and therefore which operator is being called) should also be available. Together with operators and managers we will develop an alarm mapping protocol for the plants being investigated. This protocol will form the basis for both standardization (within and between plants if required) and for the purposes of designing candidate alarm sounds.
The Alarm Sounds project should answer the following questions:
- What are the optimal sound characteristics for console alarms in multi-console control rooms for existing alarms?
- What is the optimal volume limit range as determined through human factors experiment that consider masked threshold in noise?
- Which current alarm sounds best connote urgency distinction?
- What are the optimal sound characteristics for new and improved console alarms (WAV files) in multi-console control rooms?
- New alarms may or may not take advantage of acoustical parameters such as:
- Spectral (frequency) content
- Temporal (time-based) variations
- Level (intensity)
- Modulation of a parameter
- Frequency
- Amplitude
- New alarms may or may not take advantage of acoustical parameters such as:
- Using human factors experiment what values of acoustical parameters provide effective and improved operator alarms in a control room environment?
- What type of visual display can help get operators’ attention to identify console and urgency of an alarm?
- What volume level settings of operator consoles ensure alarms are audible in worst-case ambient noise?
The ‘Alarm Tones’ pilot project and the project report demonstrate a very common problem in areas where auditory alarms are used. The researcher for this project has recently been involved in projects in the control room of space operations and in the updating of medical device standards where very similar problems are encountered. The problems are a mixture of psychoacoustic, human factors, and implementation issues which interact with one another. Given the very traditional nature of the alarm sounds currently in use, and the set of problems that go with this, researchers advocated that the starting point is to take a game-changing approach to improving the auditory alarms. In doing so, the residual problems will be smaller and will also be more clearly identifiable, and can then be treated as a set of implementation and general noise issues. For example, better auditory alarm design will reduce the signal-to-noise ratio required for detection, will increase the localizability of alarm sounds, and will reduce the amount of learning and confusion, even before standardization occurs which will improve the situation further. Thus the nature and extent of the more general problem is likely to be moderated by the preceding alarms work, and thus its solution should follow from it.
The deliverable for part 1 is the Alarm Mapping Protocol. This will take the form of a document (one-page diagram plus 1-2 page documentation) setting out how the hazards and priorities fit within the protocol and is intended as a template for standardization of the alarms used in control rooms.