Absolute Threshold: Examples, Definition & Quiz

  • Lesson
  • Quiz
  • Like?
Taught by

Sarah Cobarrubias

In this lesson, we'll talk about what absolute threshold is and explore some examples of absolute threshold for the human senses - specifically for vision and hearing. In the end, test your knowledge with a quiz.

We also recommend watching What Is the DSM? - Definition, Lesson & Quiz and Dependence on Hallucinogens: Definition and Examples

Absolute Threshold Defined

Have you ever heard the story of the Pea and the Princess? In this fairy tale, a prince is seeking a princess to take for his wife and, as luck would have it, a young woman claiming to be a princess seeks shelter from the rain at his castle. The prince's mother conducts a test to determine the authenticity of the woman's royal status - she is a princess if she can feel the presence of a pea in the bed she spends the night in, which is covered by 20 mattresses and as many featherbeds. The woman wakes in the morning complaining of a sore back from a lump in the bed, and the prince is overjoyed to have finally found a princess to marry.

It's safe to assume that the princess has a very sensitive back to be able to feel a stimulus with such a low absolute threshold. Absolute threshold is the smallest level of energy required by an external stimulus to be detectable by the human senses, including vision, hearing, taste, smell and touch. It is more precisely defined as the degree of intensity of a stimulus necessary to correctly detect that stimulus 50% of the time. Stimuli at or above the absolute threshold - those which can be detected - are called supraliminal.

Examples

Since we use our senses all the time, absolute threshold plays a part in everything we do. Here are examples of absolute threshold for each of the five senses:

Examples of Absolute Thresholds

Let's delve further into two of these senses - vision and hearing.

Vision

Absolute threshold concerning vision is the smallest amount of light that you can detect. Imagine, for instance, a car with its headlights on is driving toward you in the dark night. At first, you can't see the car, because it is too far away (the headlights are not intense enough) for you to detect. But, at some point, you are able to see the headlights, because it reached your absolute threshold.

In 1942, three researchers, Hecht, Schlaer and Pirenne, conducted a groundbreaking experiment in absolute threshold in vision. They displayed flashing lights of different intensities to human subjects in order to determine the lowest level of light that humans could detect. This experiment revealed that the human eye can detect a stimulus of as little as 90 photons.

Hearing

In hearing, absolute threshold is the smallest level of tone that you can detect, considering you have normal hearing and there are no interfering sounds. For example, you might not be able to hear someone whispering from 20 feet away, but if that person speaks up to a normal voice, it may reach your absolute threshold. Children tend to have lower absolute thresholds than adults - a child can detect a sound as low as 1,000 Hz.

Absolute Threshold for Hearing

Lesson Summary

Absolute threshold is the lowest level of energy necessary from a stimulus for it to be detectable by the human senses. More specifically, it is the smallest degree of intensity of a stimulus needed to detect that stimulus half of the time. In vision, for instance, absolute threshold is the lowest level of light the human eye can detect. In hearing, it is the lowest level of tone the human ear can detect.

Ace Your Next Test & Improve your Grades

As a member, you'll get unlimited access to over 5,000+ video lessons in Math, English, Science, History, and more. Plus, get practice tests, quizzes, and personalized coaching to help you succeed. Learn More

Start your free trial to take this quiz
As a premium member, you can take this quiz and also access over 8,500 fun and engaging lessons in math, English, science, history, and more. Get access today with a FREE trial!
Free 5-day trial
It only takes a minute to get started. You can cancel at any time.
Already registered? Login here for access.


  • Psychology Courses
  • Supplemental Lessons
  • Popular Articles

Search Our Courses

Did you like this?
Yes No

Thanks for your feedback!

What didn't you like?

What didn't you like?

Education Portal Video Lessons

The smarter way to study Short videos, Real results
  • More affordable than tutoring
  • All major high school and college subjects
  • Unlimited access to all 8,500+ video Lessons
  • Study on your own schedule
Try it Free
Copyright