Search research articles

ABOUT JoVE

Overview Leadership Blog JoVE Help Center

AUTHORS

Publishing Process Editorial Board Scope & Policies Peer Review FAQ Submit

LIBRARIANS

Testimonials Subscriptions Access Resources Library Advisory Board FAQ

RESEARCH

JoVE Journal Methods Collections JoVE Encyclopedia of Experiments Archive

EDUCATION

JoVE Core JoVE Business JoVE Science Education JoVE Lab Manual Faculty Resource Center Faculty Site

Terms & Conditions of Use

Related Concept Videos

The Cochlea

The Cochlea

The cochlea is a coiled structure in the inner ear that contains hair cells—the sensory receptors of the auditory system. Sound waves are transmitted to the cochlea by small bones attached to the eardrum called the ossicles, which vibrate the oval window that leads to the inner ear. This causes fluid in the chambers of the cochlea to move, vibrating the basilar membrane.

Hair Cells

Hair Cells

Hair cells are the sensory receptors of the auditory system—they transduce mechanical sound waves into electrical energy that the nervous system can understand. Hair cells are located in the organ of Corti within the cochlea of the inner ear, between the basilar and tectorial membranes. The actual sensory receptors are called inner hair cells. The outer hair cells serve other functions, such as sound amplification in the cochlea, and are not discussed in detail here.

Auditory Pathway

Auditory Pathway

Auditory pathways constitute the complex neural circuits responsible for transmitting and interpreting auditory information from the peripheral auditory system to the brain. Sound waves are initially captured by the outer ear, funneled through the ear canal, and reach the tympanic membrane (eardrum). These vibrations are transmitted via the middle ear's ossicles to the inner ear's cochlea.
When viewed cross-sectionally, the cochlea reveals the scala vestibuli and scala tympani flanking...

Hearing

Hearing

When we hear a sound, our nervous system is detecting sound waves—pressure waves of mechanical energy traveling through a medium. The frequency of the wave is perceived as pitch, while the amplitude is perceived as loudness.

Anatomy of the Ear

Anatomy of the Ear

Auditory sensation, commonly called hearing, involves the transformation of sonic waves into neural impulses facilitated by the structures of the auditory organ. The prominent, flesh-like structure on the side of the head, called the auricle, directs sound waves towards the auditory canal. The auricle is often mislabeled as the pinna, a term more aligned with mobile structures like a feline's external ear. The auditory canal penetrates the cranium via the external auditory meatus of the...

Perceiving Loudness, Pitch, and Location

Perceiving Loudness, Pitch, and Location

The human brain perceives pitch through two primary mechanisms reflected in place theory and frequency theory. Each mechanism describes how sound waves are interpreted as specific pitches by the brain, offering insights into the intricate processes of auditory perception.
Place theory, or place coding, suggests that different pitches are heard because various sound waves activate specific locations along the cochlea's basilar membrane. The brain determines the pitch of a sound by...

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by

Same author

Timing and risk factors for peristomal granulation in pediatric tracheostomy patients.

International journal of pediatric otorhinolaryngology·2026

Same author

Gut-Derived GLP-1 Released by Rare Sugar d-Allulose Cooperates With Insulin to Activate Left-Sided Vagal Afferents and Enhance Insulin Sensitivity.

Diabetes·2026

Same author

Clinical Impact of Nivolumab in Sinonasal Mucosal Melanoma: A 14-Year Single-Center Retrospective Study and Comprehensive Literature Review.

Cancers·2026

Same author

Relationship Between Regulation of Polysialic Acid Expression and Brain Diseases.

Advances in experimental medicine and biology·2026

Same author

The Cochlear Lateral Wall as a Biological Battery: the Mechanisms Underlying K<sup>+</sup> Transport and Potential Generation.

Journal of the Association for Research in Otolaryngology : JARO·2026

Same author

Abdominal ultrasound activates afferent vagus nerve fibers and induces anti-inflammatory effects.

Proceedings of the National Academy of Sciences of the United States of America·2026

Search research articles

Related Experiment Video

Updated: Jun 19, 2025

Morphological and Functional Evaluation of Ribbon Synapses at Specific Frequency Regions of the Mouse Cochlea

Morphological and Functional Evaluation of Ribbon Synapses at Specific Frequency Regions of the Mouse Cochlea

Published on: May 10, 2019

The cochlear hook region detects harmonics beyond the canonical hearing range.

Kazuhiro Horii¹, Bakushi Ogawa^1,2, Noriko Nagase^1,2

¹Division of Biological Principles, Department of Physiology and Biophysics, Graduate School of Medicine, Gifu University, 1-1 Yanagido, Gifu, 501-1194, Japan.

|July 26, 2024

Summary

Scientists discovered how guinea pigs hear ultrasound, finding that hair cells in the cochlea respond to high-frequency sounds. This research sheds light on ultrasonic hearing mechanisms and potential applications for hearing aids.

Keywords:

auditory brainstem response cochlear microphonic potential optical coherence tomography tonotopy ultrasonic hearing

More Related Videos

Cochlear Surface Preparation in the Adult Mouse

Cochlear Surface Preparation in the Adult Mouse

Published on: November 6, 2019

Investigating Outer Hair Cell Motility with a Combination of External Alternating Electrical Field Stimulation and High-speed Image Analysis

Investigating Outer Hair Cell Motility with a Combination of External Alternating Electrical Field Stimulation and High-speed Image Analysis

Published on: July 18, 2011

Related Experiment Videos

Last Updated: Jun 19, 2025

Morphological and Functional Evaluation of Ribbon Synapses at Specific Frequency Regions of the Mouse Cochlea

Morphological and Functional Evaluation of Ribbon Synapses at Specific Frequency Regions of the Mouse Cochlea

Published on: May 10, 2019

Cochlear Surface Preparation in the Adult Mouse

Cochlear Surface Preparation in the Adult Mouse

Published on: November 6, 2019

Investigating Outer Hair Cell Motility with a Combination of External Alternating Electrical Field Stimulation and High-speed Image Analysis

Investigating Outer Hair Cell Motility with a Combination of External Alternating Electrical Field Stimulation and High-speed Image Analysis

Published on: July 18, 2011

Area of Science:

Auditory Neuroscience
Bioacoustics
Sensory Physiology

Background:

Ultrasound, frequencies beyond human hearing, is perceived by some animals and has applications in brain activation and hearing aids.
The physiological basis for ultrasonic hearing, especially in mammals, remains largely unexplored.
Understanding ultrasonic perception is crucial for advancing audiology and neuroscience.

Purpose of the Study:

To elucidate the physiological mechanism of ultrasonic hearing in mammals.
To investigate the role of cochlear hair cells and the sensory epithelium in detecting ultrasound.
To determine the frequency range and characteristics of ultrasonic sound detection in the cochlea.

Main Methods:

Evoked auditory brainstem responses and cochlear microphonic potentials (CM) in guinea pigs exposed to ultrasound.
In vivo optical nano-vibration analysis of the cochlear sensory epithelium.
Electrophysiological recordings to assess mechano-electrical transduction in hair cells.

Main Results:

Ultrasound above the typical hearing range elicits auditory brainstem responses and CM in guinea pigs.
Cochlear hair cells exhibit active and nonlinear amplification of ultrasonic stimuli, synchronizing with the sound.
The cochlear hook region resonates with ultrasound and its harmonics, detecting frequencies over two octaves beyond the normal hearing limit.

Conclusions:

Mammalian cochlear hair cells are capable of responding to ultrasonic frequencies and their harmonics.
The basal extreme of the cochlea, specifically the hook region, plays a key role in detecting high-frequency ultrasound.
This study reveals a previously unknown mechanism for ultrasonic hearing, with implications for hearing aid technology and understanding sensory perception.