Related Experiment Video
Updated: May 31, 2026
07:20
Observing the Transformation of Bodily Self-consciousness in the Squeeze-machine Experiment
Published on: March 8, 2019
Pushing the envelope of sound
1UCL Ear Institute, London WC1X8EE, UK. j.ashmore@ucl.ac.uk
Neuron
|June 22, 2011
Summary
Sound amplification in the cochlea is crucial for normal hearing. Prestin-based amplification is a viable mechanism, overcoming previous limitations related to the outer hair cell
Area of Science:
- Auditory Neuroscience
- Cellular Biophysics
Background:
- Normal hearing relies on the cochlea's ability to amplify sound.
- Outer hair cells (OHCs) play a critical role in cochlear amplification.
Discussion:
- The study investigates the role of prestin in OHC electromotility.
- It addresses the previously proposed limitation of the OHC membrane time constant on amplification speed.
Key Insights:
- Prestin-based amplification is demonstrated to be a viable mechanism for cochlear sound amplification.
- The outer hair cell's membrane time constant does not limit prestin-driven amplification as previously thought.
Outlook:
- This finding may necessitate a re-evaluation of models of cochlear mechanics.
- Further research could explore the precise molecular mechanisms and physiological relevance of this unimpeded amplification.
Related Concept Videos
01:17Sound as Pressure Waves
Sound waves, which are longitudinal waves, can be modeled as the displacement amplitude varying as a function of the spatial and temporal coordinates. As a column of the medium is displaced, its successive columns are also displaced. As the successive displacements differ relatively, a pressure difference with the surrounding pressure is created. The gauge pressure varies across the medium.
The pressure fluctuation depends on the difference in displacements between the successive points in the...
The pressure fluctuation depends on the difference in displacements between the successive points in the...
00:53Sound Waves: Interference
Sound waves can be modeled either as longitudinal waves, wherein the molecules of the medium oscillate around an equilibrium position, or as pressure waves. When two identical waves from the same source superimpose on each other, the combination of two crests or two troughs results in amplitude reinforcement known as constructive interference. If two identical waves, that are initially in phase, become out of phase because of different path lengths, the combination of crests with troughs...
01:12Korotkoff Sounds
Korotkoff sounds are the specific sounds heard while measuring blood pressure using a sphygmomanometer, typically with a stethoscope or a Doppler device. They are named after Russian physician Nikolai Korotkov, who first described them in 1905. These sounds correspond to turbulent blood flow in the artery as the blood pressure cuff is gradually released after inflation.
During blood pressure assessment, inflating the cuff 30 millimeters of mercury above the patient's systolic blood pressure...
During blood pressure assessment, inflating the cuff 30 millimeters of mercury above the patient's systolic blood pressure...
01:14Sound Waves: Resonance
Resonance is produced depending on the boundary conditions imposed on a wave. Resonance can be produced in a string under tension with symmetrical boundary conditions (i.e., has a node at each end). A node is defined as a fixed point where the string does not move. The symmetrical boundary conditions result in some frequencies resonating and producing standing waves, while other frequencies interfere destructively. Sound waves can resonate in a hollow tube, and the frequencies of the sound...
01:01Sound Waves
Sound waves can be thought of as fluctuations in the pressure of a medium through which they propagate. Since the pressure also makes the medium's particles vibrate along its direction of motion, the waves can be modeled as the displacement of the medium's particles from their mean position.
Sound waves are longitudinal in most fluids because fluids cannot sustain any lateral pressure. In solids, however, shear forces help in propagating the disturbance in the lateral direction as well. Hence,...
Sound waves are longitudinal in most fluids because fluids cannot sustain any lateral pressure. In solids, however, shear forces help in propagating the disturbance in the lateral direction as well. Hence,...
00:58Sound Intensity
The loudness of a sound source is related to how energetically the source is vibrating, consequently making the molecules of the propagation medium vibrate. To measure the loudness of a source, the physical quantity of interest is the intensity. This is defined as the energy emitted per unit of time per unit of area perpendicular to the sound wave's propagation direction. Since the total energy is greater if the source vibrates for a longer duration and over a larger area, dividing the emitted...