Auditory Perception Threshold

The auditory system is essential for sound perception, utilizing various critical structures. When sound waves enter the outer ear, they travel through the ear canal and cause the eardrum to vibrate. These vibrations are then transmitted to the middle ear, where three tiny bones – the malleus, incus, and stapes – amplify the sound. This amplification is crucial, as it ensures that the sound vibrations are strong enough to be conveyed to the inner ear. These vibrations then reach the cochlea, a...

Source: Laboratory of Jonathan Flombaum—Johns Hopkins University The study of sensation—how signals are transduced from sensory organs, like the eyes—and perception—how the brain interprets these messages—has a rich history dating back to the 19th century, when great strides were made in understanding the properties of light and how they relate to the visual system. Importantly, such sensory and perceptual processes determine what we see, feel, taste, and hear in our surroundings. However, many...

Source: Laboratory of Jonathan Flombaum—Johns Hopkins University Psychophysics is the name for a set of methods in perceptual psychology designed in order to relate the actual intensity of stimuli to their perceptual intensity. One important aspect of psychophysics involves the measurement of perceptual thresholds: How bright does a light need to be for a person to be able to detect it? How little pressure applied to the skin is detectable? How soft can a sound be and still be heard? Put...

Source: Lee, D., et. al. Modified Experimental Conditions for Noise-Induced Hearing Loss in Mice and Assessment of Hearing Function and Outer Hair Cell Damage. J. Vis. Exp. (2023)This video demonstrates the measurement of auditory brainstem response (ABR) in a mouse. Electrodes are placed on the head, behind the ear, and near the tail of an anesthetized mouse. Acoustic stimuli at various intensities are delivered, and electric signals generated are recorded as waveforms.

Source: Laboratories of Jonas T. Kaplan and Sarah I. Gimbel—University of Southern California Imagine the sound of a bell ringing. What is happening in the brain when we conjure up a sound like this in the "mind's ear?" There is growing evidence that the brain uses the same mechanisms for imagination that it uses for perception.1 For example, when imagining visual images, the visual cortex becomes activated, and when imagining sounds, the auditory cortex is engaged. However, to what extent are...