Understanding Echoic Memory: How We Process Sound
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 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.
Echoic memory continually processes sound from our environment. An echoic memory example is seen in conversation. Music and conversation are immediately processed by echoic memory to allow the brain to interpret words and their meaning. Echoic memory occurs automatically whether a person consciously tries to remember what they've heard. Echoic memory is the brief sensory memory of audible sounds. An echoic memory example occurs with conversation. Echoic memory allows the brain to retain spoken syllables in order for the brain to process them into intelligible speech.
A German American psychologist by the name of Ulric Neisser defined the concept of echoic memory in 1967.
To better understand how echoic memory fits into the larger context of memory, let's take a quick look at how human memory systems are structured. According to the Atkinson-Shiffrin theory of memory, memory is comprised of three major components: sensory, short-term, and long-term. Echoic memory is a type of sensory memory. As the name implies, sensory memory involves detecting and maintaining sensory information for potential use.
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.
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 constantly “on,” meaning that your brain automatically picks up sounds and stores them, albeit briefly.
The brain processes auditory information from echoic memory in the primary auditory cortex (PAC). The PAC of the left ear stores sounds heard with the right ear and vice versa. Sounds heard with both ears are stored in bilateral PACs. Echoic memory is processed in the left hemisphere of the brain. The left hemisphere of the brain primarily processes echoic memory.
In the early 1960s, George Sperling conducted ground-breaking research pertaining to visual sensory memory, otherwise known as iconic memory. Sperling designed and carried out studies that illuminated how the visual sensory memory system works. Naturally, this influenced others to look closely at other sensory memory processes as well. Not long after Sperling's research on iconic memory, cognitive psychologist Ulric Neisser popularized the term echoic memory, referencing the auditory equivalent of what Sperling had discovered in the realm of visual sensory memory. Since the work of Sperling and Neisser, echoic memory has been studied extensively around the world by cognitive psychologists.
Duration of Echoic Memory
How Long Does Echoic Memory Last? Echoic memory lasts three to four seconds before the information disappears. If someone wishes to remember the brief burst of information in their echoic memory, they must consciously transfer the auditory information into their short-term memory.
Examples of Echoic Memory
Here are a few everyday 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. An echoic memory example is demonstrated with music. Notes played on a piano are stored in echoic memory long enough for the brain to process the notes into a recognizable song or melody. Echoic memory allows the brain to interpret individual notes into a recognizable 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. When someone is distracted and asks a friend, "What did you say?" Echoic memory is the reason that they immediately recognize the words even when they weren't actively listening to the conversation. The person's echoic memory retained the words even though it was not done consciously. Echoic memory allows the recall of words that were spoken when not listening.
This brief duration means your brain can make many echoic memories throughout the day. All humans have echoic memory. However, various factors can influence how well someone has this type of memory.
Factors Affecting Echoic Memory
Possible 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
- Language (with spoken word)
Echoic Memory vs. Iconic Memory
Iconic memory, or visual sensory memory, holds visual information. It’s a type of sensory memory, just like echoic memory. Iconic memory is sensory memory from visual input.
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.
When to Seek Medical 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.
Additional Research on Echoic Memory
In 1974, Graham Hitch and Alan Baddeley proposed a human memory model with a phonological loop that attends in two ways to auditory stimuli. This system supposedly comprises an initial 200 to 400-ms input phase followed by an information transferring phase.
Likewise, the subjects in the echoic memory experiments had to repeat sequences of syllables, words, or tones that they heard. ABRM involves presenting a brief target stimulus to the subjects and then, following a brief interval, presenting the mask [a second stimulus]. Performance seems to improve as the interstimulus interval is raised to 250ms.
Echoic memory involves several distinct brain regions on account of its various processes. As mismatch negativity research suggests, such cognitive and developmental growth is likely to occur until adulthood before experiencing a decline in old age.
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.
Audible aspects of verbal communication include the smaller sounds that make up the words. 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.
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.
One fun experiment you can try is to sing a song with another person or with a recording. 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.
Echoic memory is a subcategory of human memory, which can be divided into three major categories:
- Long-term memory retains events, facts, and skills. It can last for hours to decades.
- Short-term memory stores information you recently received. It lasts for a few seconds to 1 minute.
- 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.
- Haptic memory retains information from your sense of touch.
- Echoic memory holds audio information from your sense of hearing.
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.
| Memory Type | Duration | Sensory Input |
|---|---|---|
| Iconic Memory | Less than 0.5 seconds | Visual |
| Echoic Memory | 3-4 seconds | Auditory |
| Short-Term Memory | Seconds to 1 minute | Various |
| Long-Term Memory | Hours to decades | Various |