Related Experiment Video
Updated: Apr 11, 2026
09:07
Author Spotlight: Advancing Endoscopic Ossiculoplasty – Techniques, Innovations, and Practical Guidance for Clinical Integration
Published on: January 26, 2024
3.7K
Negative Middle Ear Pressure and Composite and Component Distortion Product Otoacoustic Emissions
Suzanne Thompson1, Simon Henin, Glenis R Long
11Department of Communication Sciences and Disorders, St. John's University, Queens, New York, USA; and 2Speech, Language, and Hearing Sciences, The Graduate Center of the City University of New York, New York, USA.
Ear and Hearing
|June 8, 2015
Summary
Negative middle ear pressure (NMEP) significantly impacts distortion product otoacoustic emissions (DPOAEs), affecting both generator and reflection components. Analyzing DPOAE components separately, particularly the generator, clarifies results during NMEP.
Area of Science:
- Audiology
- Otoacoustic Emissions
- Cochlear Physiology
Background:
- Distortion product otoacoustic emissions (DPOAEs) assess cochlear health.
- DPOAEs result from generator and reflection components.
- Negative middle ear pressure (NMEP) increases middle ear impedance, potentially affecting DPOAEs.
Purpose of the Study:
- To investigate the impact of negative middle ear pressure (NMEP) on distortion product otoacoustic emissions (DPOAEs).
- To determine if NMEP affects DPOAE components (generator and reflection).
- To assess the clinical utility of DPOAEs under NMEP conditions.
Main Methods:
- Recruited 26 normal-hearing subjects, with 8 inducing NMEP via Toynbee maneuver.
- Collected tympanic peak pressure (TPP) and DPOAEs under normal and NMEP conditions.
- Analyzed DPOAE and component magnitudes across frequencies and primary levels using ANOVA.
Main Results:
- Subject-induced NMEP ranged from -65 to -324 daPa.
- NMEP significantly affected composite DPOAE and component levels across tested frequencies.
- Generator component changes were most pronounced, with one subject showing a 12 dB decrease.
Conclusions:
- NMEP significantly impacts DPOAE composite and component levels.
- Separating DPOAE components, especially the generator, aids interpretation under NMEP.
- Findings highlight NMEP as a factor influencing DPOAE measurements in clinical settings.
Related Concept Videos
01:11The 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...
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
01:16Anatomy 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
01:20¹³C NMR: Distortionless Enhancement by Polarization Transfer (DEPT)
1.9K
When proton-coupled carbon-13 spectra are simplified by a broadband proton decoupling technique, structural information about the coupled protons is lost. Distortionless enhancement by polarization transfer (DEPT) is a technique that provides information on the number of hydrogens attached to each carbon in a molecule. While the DEPT experiment utilizes complex pulse sequences, the pulse delay and flip angle are specifically manipulated. The resulting signals have different phases depending on...
1.9K
01:17Sound as Pressure Waves
4.9K
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...
4.9K
01:25Instrumentation Amplifier
1.3K
An electrocardiography (ECG) machine is an essential piece of medical equipment used to monitor the electrical activity of the heart. It operates by detecting small electrical changes on the skin that result from the depolarization of the heart muscle during each heartbeat. However, these signals are in the microvolt range and can be easily overwhelmed by noise or interference.
To overcome this challenge, an ECG machine utilizes an instrumentation amplifier. This specialized amplifier is...
To overcome this challenge, an ECG machine utilizes an instrumentation amplifier. This specialized amplifier is...
1.3K
00:53Sound Waves: Interference
5.2K
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...
5.2K