Echoic memory, or auditory sensory memory, is a type of memory that stores audio information (sound).
It’s 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.
Let’s look at how echoic memory works and how long it lasts, along with real-life examples.
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. 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.
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.
Echoic memory is very short. According to the “Handbook of Neurologic Music Therapy,” it only lasts for 2 to 4 seconds.
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.
Possible factors include:
- 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:
- language (with spoken word)
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.
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
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.
But if you’re experiencing severe memory problems, it’s best to seek medical help.