Why Sound is Such a Powerful Memory Trigger
Updated: Oct 27, 2021
Echoic memory, which holds audio information from your sense of hearing, lasts only 2 to 4 seconds.
One of the most common questions we’re asked here at ChromeOrange Media is why we say in our webinar, “Brands Like Hit Songs,” that sound used in marketing and branding is more memorable than visuals (including brand logos) are.
The answer to that question lies in the types of memory our human brain stores:
Echoic memory, or auditory sensory memory, is a type of memory that stores audio information—sound, music, ambient noise and sound effects.
Echoic memory is a subcategory of human memory, which has six parts:
Long-term memory retains events, facts, and skills. It can last anywhere from hours to decades.
Short-term memory stores information recently received. It lasts anywhere from 30 seconds to several hours.
Sensory memory, also called the sensory register, holds information from the senses. It can be further broken down into three types:
Iconic memory, or visual sensory memory, handles visual information. Lasts for less than a half second.
Haptic memory retains information from your sense of touch. These memories tend to last for about two seconds. It enables us to combine a series of touch sensations and to play a role in identifying objects we can’t see.
Echoic memory holds audio information from your sense of hearing. Lasts only 2 to 4 seconds.
The difference between short- and long-term memory can be compared to a computer. The information in your long-term memory would be like the information you have saved on your hard drive. It isn’t there on your desktop (your short-term memory), but you can pull it up whenever you want or need it, at least most of the time.
The purpose of echoic memory is to store audio information as the brain processes the sound. It also holds bits of audio information, which gives meaning to the overall sound.
How echoic memory works
When you hear something, your auditory nerve transmits electrical signals to your brain— “sends” the sound to it. While this is happening, the sound is “raw,” unprocessed audio information.
Echoic memory occurs when the brain receives and holds this audio information. Specifically, the information is stored in the primary auditory cortex (PAC), which is found in both hemispheres of the brain.
The information is held in the PAC opposite of the ear that heard the sound. For instance, if you hear a sound in your right ear, the left PAC will hold the memory. But if you hear a sound through both ears, both the left and right PAC will retain the information.
After a few seconds, the echoic memory moves into your short-term memory, where your brain processes the information and gives meaning to the sound.
Echoic memory is automatic. This means that audio information enters your echoic memory even if you aren’t actively and purposefully listening. In fact, our minds constantly form echoic memories. For example, when you talk with someone, your echoic memory retains each individual syllable. Your brain recognizes words by connecting each syllable to the previous one. Similarly, each word is also stored in echoic memory, thus enabling your brain to understand a full sentence.
Your brain also uses echoic memory when you listen to music. It briefly recalls the previous note and connects it to the next one. As a result, your brain recognizes the notes as a song. The same holds true for sonic (audio) logos.
Iconic memory vs. echoic memory
Echoic memory is very short. According to the “Handbook of Neurologic Music Therapy,” it only lasts for 2 to 4 seconds.
Iconic memory, or visual sensory memory, on the other hand, holds visual information. It’s a type of sensory memory, just like echoic memory, but it’s much shorter, lasting for less than a half second.
The reason for the discrepancy in the durations of iconic and echoic memory is that images and sounds are processed differently. Since most visual information doesn’t immediately disappear, you can repeatedly view an image. Plus, when you look at something, you can process all the visual images together.
Echoic memory is longer because sound waves are time sensitive. They can’t be reviewed unless the actual sound is repeated.
Also, sound is processed by individual bits of information. Each bit gives meaning to the previous bit, which then gives meaning to the sound. As a result, the brain needs more time to store audio information.
The goal is long-term memory
Eventually, when your brain has repeatedly been exposed to and recalled both sound and visual information, it moves up the memory hierarchy to long-term memory—the stage in which information is stored indefinitely. It is defined in contrast to short-term memory, which typically lasts for only about 18 to 30 seconds but can sometimes last for several hours, whereas long-term memory lasts anywhere from hours to decades.
For marketers and brand managers, long-term memory is the goal. We want consumers to remember the sound and visuals we’ve attached to our brand messaging as well as the music we pair with them in our broadcast advertising. That’s where the “Rule of 3” comes in. More on that in our next blog post.