Jove
Visualize
Contact Us
JoVE
x logofacebook logolinkedin logoyoutube logo
ABOUT JoVE
OverviewLeadershipBlogJoVE Help Center
AUTHORS
Publishing ProcessEditorial BoardScope & PoliciesPeer ReviewFAQSubmit
LIBRARIANS
TestimonialsSubscriptionsAccessResourcesLibrary Advisory BoardFAQ
RESEARCH
JoVE JournalMethods CollectionsJoVE Encyclopedia of ExperimentsArchive
EDUCATION
JoVE CoreJoVE BusinessJoVE Science EducationJoVE Lab ManualFaculty Resource CenterFaculty Site
Terms & Conditions of Use
Privacy Policy
Policies

Related Concept Videos

Perceiving Loudness, Pitch, and Location01:21

Perceiving Loudness, Pitch, and Location

1.3K
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...
1.3K
The Cochlea01:13

The Cochlea

52.7K
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.
52.7K
Hearing01:31

Hearing

59.0K
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.
59.0K
Hair Cells01:22

Hair Cells

46.8K
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.
46.8K
Anatomy of the Ear01:16

Anatomy of the Ear

14.0K
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...
14.0K
The Auditory Ossicles01:11

The Auditory Ossicles

3.9K
The auditory ossicles of the middle ear transmit sounds from the air as vibrations to the fluid-filled cochlea. The auditory ossicles consist of two malleus (hammer) bones, two incus (anvil) bones, and two stapes (stirrups), one on each side. These bones develop during the fetal stage and are the ones to ossify first. They are fully mature at birth and do not grow afterward.
The aptly named stapes look very much like a stirrup. The three ossicles are unique to mammals, and each plays a role in...
3.9K

You might also read

Related Articles

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

Sort by
Same author

Inhibitory inputs to avian ITD circuits.

Trends in hearing·2026
Same author

A general mechanism of airborne hearing in recent and early non-tympanate tetrapods.

The Journal of experimental biology·2026
Same author

An International Interdisciplinary Commentary on the Revised Guidelines for Music-based Interventions Checklist, Elaboration Guide and Validation Study.

Journal of music therapy·2026
Same author

Organization of the Auditory Brainstem in a Lizard, Gekko gecko. II. Afferent and Efferent Projections of Nuclei of the Lateral Lemniscus and the Torus Semicircularis.

The Journal of comparative neurology·2025
Same author

Single Neuron Contributions to the Auditory Brainstem EEG.

The Journal of neuroscience : the official journal of the Society for Neuroscience·2025
Same author

Auditory pathway for detection of vibration in the tokay gecko.

Current biology : CB·2024
Same journal

Multivariate prediction of conductive dysfunction in well and NICU newborns using wideband acoustic immittance with acoustic reflex tests.

Hearing research·2026
Same journal

TGF-β signaling regulates flat epithelium formation in severely injured adult mouse utricle through epithelial-mesenchymal transition.

Hearing research·2026
Same journal

Membrane scaffolding in auditory hair cells - a molecular tightrope walk enables lateral wall stiffness and flexibility.

Hearing research·2026
Same journal

Speech-in-noise recognition during hearing protector use: Human performance and acoustic prediction.

Hearing research·2026
Same journal

Estimation of hair cell loss from audiograms.

Hearing research·2026
Same journal

Cochlear size variation in a large-scale international multicentre cohort.

Hearing research·2026
See all related articles

Related Experiment Video

Updated: Apr 11, 2026

An Automated System for Sound Localization Testing in Hearing-Impaired Listeners
07:56

An Automated System for Sound Localization Testing in Hearing-Impaired Listeners

Published on: March 13, 2026

128

Sound localization in the alligator.

Hilary S Bierman1, Catherine E Carr1

  • 1Center for Comparative and Evolutionary Biology of Hearing, Department of Biology, University of Maryland College Park, College Park, Maryland 20742, USA.

Hearing Research
|June 7, 2015
PubMed
Summary
This summary is machine-generated.

Early tetrapod ears were directional. Later mammals and archosaurs evolved isolated middle ears, driving new strategies for sound localization, particularly in crocodilians.

Keywords:
ArchosaurAuditory peripheryBehaving alligatorBrainstem physiologyPressure-difference receiverSkull anatomy

More Related Videos

Sound Source Localization Testing in Single-sided Deafness Following Bone Conduction Intervention
04:32

Sound Source Localization Testing in Single-sided Deafness Following Bone Conduction Intervention

Published on: December 20, 2024

1.0K
Physiological Preparation of Hair Cells from the Sacculus of the American Bullfrog Rana catesbeiana
12:07

Physiological Preparation of Hair Cells from the Sacculus of the American Bullfrog Rana catesbeiana

Published on: March 17, 2017

17.4K

Related Experiment Videos

Last Updated: Apr 11, 2026

An Automated System for Sound Localization Testing in Hearing-Impaired Listeners
07:56

An Automated System for Sound Localization Testing in Hearing-Impaired Listeners

Published on: March 13, 2026

128
Sound Source Localization Testing in Single-sided Deafness Following Bone Conduction Intervention
04:32

Sound Source Localization Testing in Single-sided Deafness Following Bone Conduction Intervention

Published on: December 20, 2024

1.0K
Physiological Preparation of Hair Cells from the Sacculus of the American Bullfrog Rana catesbeiana
12:07

Physiological Preparation of Hair Cells from the Sacculus of the American Bullfrog Rana catesbeiana

Published on: March 17, 2017

17.4K

Area of Science:

  • Evolutionary biology
  • Auditory neuroscience
  • Comparative anatomy

Background:

  • Early tetrapods likely had acoustically coupled tympana, functioning as directional pressure difference receivers.
  • The evolution of isolated middle ear cavities in turtles, archosaurs, and mammals represents a derived condition that altered auditory capabilities.
  • This isolation necessitated the development of structural and neural mechanisms for sound source localization.

Purpose of the Study:

  • To review the evolution of directional hearing in tetrapods.
  • To focus on sound localization strategies in archosaurs, particularly crocodilians.
  • To highlight unresolved questions in crocodilian directional hearing.

Main Methods:

  • Comparative analysis of middle ear evolution across tetrapod lineages.
  • Review of anatomical and physiological adaptations for directional hearing.
  • Examination of ecological relevance of vocalization and sound localization in crocodilians.

Main Results:

  • The decoupling of tympana in derived tetrapods spurred adaptations for sound localization.
  • Archosaur lineages (birds, crocodilians) utilized cranial air spaces for enhanced directional hearing.
  • Neural circuits for sound localization are well-developed in archosaurs.

Conclusions:

  • The evolution of isolated middle ears drove the development of sophisticated sound localization mechanisms.
  • Crocodilians offer a key model for studying the ecological importance of directional hearing.
  • Further research is needed to fully understand the complexities of crocodilian auditory systems and sound localization.