Human beings have an incredible capability to communicate. Unlike other species, humans have evolved to use language to express our states, desires, observations, and, I guess, tweet about them. Language is a powerful system of communication because it allows the expression of counterfactuals: we can easily discuss the past and future; distant, unseen locations; complex emotional states; abstract concepts; and many things that are difficult, if not impossible, to see, hear, and feel in the real world.

But with great power comes great inscrutability. While we can look directly at a GIF and see emotional states (excitement, disgust), or look at an Emoji and see visual icons (eggplant, brain), we cannot hear the word “eggplant” and evoke the features of eggplant.

To illustrate this point, try to imagine what a “takete” might be like compared to a “maluma.” The phonemes that make up these (imaginary) words convey nothing about what a takete or maluma might look like or be. (Phonemes are the smallest unit of speech that convey meaning).

This mapping, of the sounds of a word onto the meaning of the word has often been thought to be arbitrary. We cannot derive any of the features of a takete from hearing the word because the sounds in it are not meaningfully related to the thing in the real world.

Or can we?

Sound symbolic association, a theory in modern linguistics, argues that the structure of the sounds in phonemes are not arbitrarily related to their meaning, but show systematic relationships. For example, the sounds in “takete” are sharp and abrupt – which might be why people who encounter this (imaginary) word are more likely to associate it with a sharp object than the softer-sounding, longer vowels and consonants of “maluma.” (You may recall that we’ve covered this phenomenon before on this blog with round “bouba” and pointy “kiki.”) It might also be why people can guess the meaning of (real) foreign antonyms above chance – because they’re likely to sound like what they are.

Sound symbolic associations can occur with several different degrees of iconicity – whether the form of the phoneme matches an aspect of its meaning. Sound symbolic associations occur directly in cases where the sound resembles the symbol (like onomatopoeia – “bang” or “whirr”). They also occur indirectly in cases where, for example, making the sound in “round” causes the mouth to become round. Sound symbolic associations can occur across several words – teeny (with its short, high-frequency vowel) is smaller than tiny (with its longer, lower-frequency vowel).

Examples abound of sound symbolic associations, within and across languages, but it’s unclear why. A recent paper published in Psychonomic Bulletin & Review by David Sidhu and Penny Pexman discusses five possible mechanisms behind sound symbolic associations. Of course, this list of mechanisms may not be exhaustive, and the mechanisms may also combine to create some of the sound symbolic associations that have been discovered. But for simplicity, Sidhu and Pexman discuss them one at a time. Here they are:

1. Statistical co-occurrence. Perhaps sound symbolic associations arise because dimensions of things in the world themselves tend to occur together.

• Example: Large things—such as elephants—tend to make lower frequency noises and resonate at lower frequencies than small things—such as hummingbirds. Over time, humans could have observed these co-occurrences, which would arise again in language. Front vowels (like the vowel in “min”) have a higher (second) frequency than back vowels (like the vowel in “max”). These frequencies map onto the size meanings of “minimum” and “maximum.”

2. Shared properties. Sounds may share some property directly with the things they refer to. This would mean certain sounds would naturally be paired with particular things. According to Sidhu and Pexman, this mapping could be at a perceptual level (like the sound in round, described above), or a conceptual level (like a high-frequency vowel being associated with a high-frequency tone, and relating to the concept of bright). These often occur across modalities (like, from sound to vision), which is why they are often called cross-modal perceptions (as we’ve discussed before on this blog).

• Example: Takete and maluma each share properties with sharpness and roundness that match their phonemic qualities.

3. Neural factors. Overlap in neural processing is not uncommon, and could explain why the production of some sounds corresponds with certain concepts.

• Example: Neural control of articulation of certain phonemes (like “t” versus “g”) corresponds with a precision mouth grip (opening a sunflower seed) and power mouth grip (bobbing for apples), respectively. This neural association between mouth grasping and a phoneme might result in the association between small “t” things and large “g” things.

4. Species-general associations. On an evolutionary time scale, natural selection may have put pressure on organisms to identify particular sounds, and thus gain information about their environment.

• Example: Across species, low-frequency utterances tend to indicate threats, which could be because organism are trying to appear large. Thus, evolutionary pressure would lead to better survival for organisms who associated low-frequency with large.

5. Language patterns. Like statistical co-occurrence, language pattern explanations of sound symbolic associations emphasize commonalities in meaning within language for certain phonemes.

• Example: Glow, glisten, gleam, glitter, glamour, and glory all relate to brightness and shininess and all share an initial “gl” sound, despite “gl” not having anything to do with brightness on its own.

Sound symbolic associations fly in the face of what most of us think about language – that except for a few outliers, mostly language is arbitrary. Instead, language might contain more meaningful relations that make it easier for infants to learn, for speakers to remember, and possibly for language to have evolved in the first place.

Reference for the article discussed in this post:
Sidhu, D.M., & Pexman, P.M. (2017). Five mechanisms of sound symbolic association. Psychonomic Bulletin & Review. DOI: 10.3758/s13423-017-1361-1.