Understanding Echoic Memory: How Your Brain Retains Sound
Most people are familiar with the concept of "memory" as the ability to recall events that happened previously. But what is echoic memory? 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.
Specifically, echoic memory is sensory memory associated with auditory information received from the environment. The term echoic stems from the word echo, which is in reference to the brief echo, or the reverberation of sound that is transmitted neurologically via this type of sensory memory. It’s a type of sensory memory along with iconic (visual) and haptic (touch-based).
The Basics of Echoic Memory
Echoic memory is the brief sensory memory of audible sounds. 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.
A German American psychologist by the name of Ulric Neisser defined the concept of echoic memory in 1967.
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 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.
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.
How Long Does Echoic Memory Last?
Echoic memory lasts three to four seconds before the information disappears. While echoic memory is very short, it helps keep information in your brain even after the sound has ended. 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.
Long-term memory allows someone to recall a melody or recognize bird songs that were heard years ago.
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. Echoic memory allows the brain to interpret individual notes into a recognizable song. 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.
- 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.
An echoic memory example is demonstrated with music. Echoic memory allows the brain to interpret individual notes into a recognizable song. An echoic memory example is seen in conversation. Echoic memory allows the brain to retain spoken syllables in order for the brain to process them into intelligible speech. An echoic memory example occurs with conversation.
A Funny Example: Think back to the last time you heard someone tell you a funny joke. After you finished laughing, you probably either repeated it out loud, or at minimum, replayed what you just heard over again in your head. Chances are that if you were asked to repeat the joke word for word immediately after you heard it, assuming it wasn't too long, you would do pretty well.
Factors Influencing Echoic Memory
All humans have echoic memory. However, various factors can influence how well someone has this type of 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.
| Feature | Echoic Memory | Iconic Memory |
|---|---|---|
| Type of Sensory Input | Auditory (Sound) | Visual (Sight) |
| Duration | 3-4 seconds | Less than 0.5 seconds |
| Processing | Sequential bits of information | All visual information together |
Discovery of 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. The work of men like Sperling and Neisser has contributed greatly to the development of the knowledge base on sensory and echoic memory that we possess today.
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.
Memory testing in both iconic and echoic memory defined the difference between whole and partial reporting. When testing echoic memory, someone is given a series of spoken letters or numbers. They are less able to give a whole report and recall all of the spoken letters. If asked to recall a specific portion of the spoken letters, the partial recall is much higher and accurate. Partial reporting surpasses accuracy when compared to the whole reporting.