Category Archives: Phonetic Alphabet

Human Performance Tool Spotlight: Phonetic Alphabet


Hi there Human Performance Toolbox Community! I have recently been teaching some human performance fundamentals classes and have been asked to share content with my website visitors, and I love to share and trade human performance improvement information. So, over the next few weeks, I will be publishing a lot of human performance tool (HPT) content specific to the tools field workers should be using. As a reminder, tools are only part of a human performance improvement initiative and they are only to be used when they matter the most, which often is in preparation of managing a critical step, or recognizing you’re in an error-likely situation. Feel free to drop a note if this is helpful to you and your program!

Phonetic Alphabet

As part of an overall “Effective Communication” effort (in combination with Three-Part Communication), this tool is designed to ensure the message sent is the message received, and yes, this should become part of the fabric in your communication culture when the message has undesirable consequences if not transmitted or received adequately.


Several letters in the English language sound alike and can be confused in stressful or noisy situations. The phonetic alphabet specifies a word for each letter of the English alphabet. By using a word for each letter there is less chance that the person listening will confuse the letters. For example, some letters sound alike when spoken and can easily be confused such as “D” and “B”. Using the phonetic alphabet, “Delta” and “Bravo” are more easily differentiated. The effects of noise, weak telephone or radio signals, and an individual’s accent are reduced through the use of the phonetic alphabet.

People use the phonetic alphabet and unit designators when describing unique identifiers for specific components.   When the only distinguishing difference between two component labels is a single letter, then the phonetic alphabet form of the letter should be substituted for the distinguishing character. For example, 2UL-18L and 2UL-18F would be stated “two U L eighteen LIMA” and “two U L eighteen FOXTROT.” Using the phonetic alphabet is unnecessary when using standard approved acronyms depending on your industry, such as “RHR” (residual heat removal) for Westinghouse Pressurized Water Reactors.

When communicating operational information important to safety, people can use key words to convey specific meanings. For instance, individuals use the term “STOP” to immediately terminate any action or activity to avoid harm. “CORRECT” confirms understanding. “WRONG” conveys an incorrect understanding of the meaning of the intended message. Similarly, other words can be reserved for special meanings related to the organization’s operational activities.

NATO link to the alphabet:

For the Love of all that is good. Learn this….

When to use the tool:

  • When communicating alphanumeric information related to plant equipment noun names
  • When specifying train, phase, and channel designations
  • When the sender or receiver might misunderstand, such as sound-alike systems, high noise areas, poor reception during radio or telephone communications

At risk practices:

  • Not using phonetics for equipment label designations, safeguard trains, electrical phases, or channel designations
  • Using phonetic words other than those designated
  • Not having a standard list of accepted acronyms and abbreviations
  • Using similar-sounding words that have different meanings such as increase and decrease
  • Using slang terms (D= “Dog“) instead of specific or standard terms


With much gratitude, a lot of the above HPT basis comes from Department of Energy (DOE) and Institute of Nuclear Power Operations (INPO) research and collaboration, and the source document could be found by clicking here.

This article (you would have to purchase – sorry, it’s not free to share) adds some more specificity to the discussion : Engaging Workers as the Best Defense Against Errors & Error Precursors by Jan K. Wachter and Patrick L. Yorio

Me. I’ve inserted a few twists and clarifications for users and myself.