What is the difference between "acoustic" and "audio"?

What is the difference between "acoustic" and "audio"?

Background:
When I think of the class of data in the binary computer file, I don't know the difference. One of my coworkers asserts that it is acoustic and not audio. I treat it as data. It is non-musical data.

I'm guessing that my coworker understand acoustic to imply a more technical measurement, while audio is more about humans doing the listening.

When I look at Merriam-Webster, the definitions suggest that audio is more appropriate than acoustic, acoustic relating to qualitative and audio relating to measurement.

Form of the answer:

  • A comment is good, but not an answer. It should be an actual answer.
  • It can state the difference, but should have some (hopefully authoritative) reference/s indicating difference.
  • A good dictionary or encyclopedia would qualify, but I don't know that such a source for this particular problem exists.
  • The reference can be a credible authors work, not exclusively a dictionary or encyclopedia. If Asimov or IEEE has a definition here, that would count.

Where I have looked so far:
Links:

  • https://www.merriam-webster.com/dictionary/acoustic
  • https://www.merriam-webster.com/dictionary/audio
  • Differences between "audio" and "sound"?
  • https://howthingsfly.si.edu/ask-an-explainer/what-difference-between-acoustic-ultrasonic-subsonic-and-supersonic-waves
  • https://www.answers.com/Q/What_is_the_difference_between_acoustics_and_audio

The question title asks the difference between acoustic and audio but it becomes clear that the topic is computer files. The difference otherwise can be found in a dictionary.

If you look up the Wikipedia page List of file formats the word acoustic does not appear anywhere, but audio is the typical descriptor.

The page contains a section titled "Sound and music" which lists dozens of file types. Those with an A in their abbreviation are all (where stated) given as Audio, for example

AIFF, AIF, AIFC – Audio Interchange File Format

and so on.

It is true that there is a file format for acoustic data, which is given in the Wikipedia page Timeline of audio formats

Adaptive Transform Acoustic Coding (ATRAC)

but that is the only one I found which uses the word acoustic. There probably are some other file types used in specialist fields that use the term acoustic such as in studies of wave propagation in various media, but they are not a mainstream use of what is commonly known as the audio file format.


In their original meanings, acoustic and audio are synonymous; they both mean having to do with hearing. They are both based on the words for hearing, albeit in different languages (Greek and Latin, respectively).

In specific contexts, the two have, however, over time, come to be used somewhat differently. For example, an electronic gadget my have outputs labelled 'video' and 'audio'; the latter would never be labelled 'acoustic'. There is nothing in the etymology that precludes that; it just happens that the established practice is to always use audio in such contexts.

On the other hand, in the contexts that have to do with music, acoustic has acquired the sense of not involving any electronic processing of sound (as in the phrase acoustic guitar).

Thus, if the question is about the use of these terms in the technical terminology of some specialised field, then the answer should be sought in observing how the terms have been used by the established experts in that field; it is not a matter of general linguistic expertise. On the other hand, if the question is about which term to use for something that has to do with hearing, but for which neither term is yet established, then the answer is that one could use either.