Understanding Echoic Memory: Duration and Function
Echoic memory is a type of sensory memory that temporarily stores auditory information or sounds for a brief period, typically for up to 3-4 seconds. It’s a part of sensory memory and holds these sounds for a brief period, typically around 3 to 4 seconds, even after the original sound has ceased. This automatic but temporary auditory memory response is a component of sensory memory. Echoic memory has a role in our perception of auditory stimuli in our world.
Memories start by receiving sensations from our five senses. Of the five, our senses of vision and hearing are more prominent in our perception of our surroundings. Visual sensations are stored very briefly (around 200 milliseconds) in iconic memory.
Echoic memory is constantly “on,” meaning that your brain automatically picks up sounds and stores them, albeit briefly. Considering our often noisy surroundings, it’s easy to assume that our echoic memory would have trouble keeping up with the rapid-fire barrage of sounds that it receives.
Echoic Memory is the distinct sensory memory that temporarily holds representations of sounds that we hear, queued for processing further into short term memory. Sound waves cause vibrations in our eardrum, middle ear, and inner ear. We have two primary auditory cortices that very briefly retain these sound representations until they’re either abandoned or moved on to the hippocampus for processing into short-term memory.
How Echoic Memory Works
When you hear something, your auditory nerve sends the sound to your brain. It does this by transmitting electrical signals. At this point, the sound is “raw” and unprocessed audio information.
Echoic memory occurs when this information is received and held by the brain. Specifically, it’s 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. This is where your brain processes the information and gives meaning to the sound. The process of echoic memory is automatic. This means audio information enters your echoic memory even if you don’t purposely try to listen. In fact, your mind is constantly forming echoic memories.
Real-life Examples
- Talking to another person: Spoken language is a common example. When someone talks, your echoic memory retains each individual syllable. Your brain recognizes words by connecting each syllable to the previous one. Each word is also stored in echoic memory, which allows your brain to understand a full sentence.
- Listening to music: Your brain 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.
- Asking someone to repeat themselves: When someone talks to you while you’re busy, you might not fully hear what they say. If they repeat what they said, it will sound familiar because your echoic memory heard them the first time.
This brief duration means your brain can make many echoic memories throughout the day.
Factors Affecting Echoic Memory
All humans have echoic memory. However, various factors can influence how well someone has this type of memory. These factors include:
- Age
- Neurological disorders, such as Alzheimer’s disease
- Psychiatric disorders, such as schizophrenia
- Substance use
- Hearing loss or impairment
- Language disorders
It also depends on the characteristics of a sound, including: duration, frequency, intensity, volume, and language (with spoken word).
Echoic Memory vs. Iconic Memory
Echoic memory stores auditory information or sounds. It’s a type of sensory memory along with iconic (visual) and haptic (touch-based).
Iconic memory, or visual sensory memory, holds visual information. It’s a type of sensory memory, just like echoic memory. But iconic memory is much shorter. It lasts for less than half a second.
That’s because images and sounds are processed in different ways. 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, which is useful 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.
Memory Issues and When to Seek Help
We all forget things sometimes. It’s also normal to experience some memory loss as we get older. But if you’re having serious memory issues, it’s important to see a doctor.
Seek medical help if you have memory problems, such as: getting lost in familiar places, forgetting how to say common words, repeatedly asking questions, taking longer to do familiar activities, forgetting names of friends and family.
Depending on your specific issues, a doctor might refer you to a specialist, like a psychologist or neurologist.
When you hear a sound, the audio information enters your echoic memory. It lasts for 2 to 4 seconds before your brain can process the sound. While echoic memory is very short, it helps keep information in your brain even after the sound has ended.
Though we all have echoic memory, factors like age and neurological disorders can affect how well you recall sounds. It’s also normal for memory to decline with age.
Interestingly, affected echoic memory stores of stroke victims can be improved with regular listening sessions of music or other recorded verbal stimuli. Automobile horns, sirens, alarms, and other alerting mechanisms deliberately draw our attention to alert us through mismatch negativity in our normal flow of sounds. But a study of students’ ability to concentrate during an exam found that test scores of students were significantly higher when the test was administered in silence.
Have you ever had an instructor that put you to sleep? It’s not that your topic is boring. There are ways that you can enhance the delivery of information in your lecture, help your audience listen and learn better, and bypass echoic memory overload. Audible aspects of verbal communication include the smaller sounds that make up the words.
Echoic memory comes into play when we listen to music.
Further Research and Applications
George Sperling’s research on iconic memory in the 1960s subsequently inspired other researchers to test the same phenomenon utilizing similar means in the auditory domain (Darwin, Turvey & Crowder, 1972). Likewise, the subjects in the echoic memory experiments had to repeat sequences of syllables, words, or tones that they heard.
The rehearsal system and the phonological store seem to be left-hemisphere systems with increased brain activity (Kwon, Reiss & Menon, 2002). As mismatch negativity research suggests, such cognitive and developmental growth is likely to occur until adulthood before experiencing a decline in old age (Glass, Sachse & Suchodoletz, 2008).
In Baddeley’s model, the central executive combines information from both components with long-term memory. Additional studies have identified another involuntary response to discriminable differences between sounds held in echoic memory and incoming sounds.
It’s evident that echoic memory plays a strong role in verbal communication, the interpretation of tonal differences in conversation, and the development of language and vocabulary as a whole.
We’ve learned that we have many echoic memories throughout our lives and that most echoic memories are lost without our ability to recall them. Subjects weren’t able to distinguish segments that were longer than a few seconds, but were able to recognize segments that were less than two seconds long. Echoic memory continually processes sound from our environment.
One fun experiment you can try is to sing a song with another person or with a recording. But it’s not all about fun activities like sensory learning and singing. Horror and suspense movies tinker with this part of our brain all the time. William Castle was a film director who innovated many such techniques, many of which influenced Alfred Hitchcock. Never forget: movies are not nearly as visual a medium as we think.
You can also leverage your echoic memory and alternative sensory stores to create auditory sensory memory palaces instead of visualizing them. Your personal memory palaces used with proven memory training will help you improve your memory and launch your ability to recall more information than you imagined possible.
