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Event: 1008

Key Event Title

A descriptive phrase which defines a discrete biological change that can be measured. More help

Reduced, Hearing

Short name
The KE short name should be a reasonable abbreviation of the KE title and is used in labelling this object throughout the AOP-Wiki. More help
Reduced, Hearing
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Biological Context

Structured terms, selected from a drop-down menu, are used to identify the level of biological organization for each KE. More help
Level of Biological Organization

Organ term

The location/biological environment in which the event takes place.The biological context describes the location/biological environment in which the event takes place.  For molecular/cellular events this would include the cellular context (if known), organ context, and species/life stage/sex for which the event is relevant. For tissue/organ events cellular context is not applicable.  For individual/population events, the organ context is not applicable.  Further information on Event Components and Biological Context may be viewed on the attached pdf. More help
Organ term

Key Event Components

The KE, as defined by a set structured ontology terms consisting of a biological process, object, and action with each term originating from one of 14 biological ontologies (Ives, et al., 2017; Biological process describes dynamics of the underlying biological system (e.g., receptor signalling).Biological process describes dynamics of the underlying biological system (e.g., receptor signaling).  The biological object is the subject of the perturbation (e.g., a specific biological receptor that is activated or inhibited). Action represents the direction of perturbation of this system (generally increased or decreased; e.g., ‘decreased’ in the case of a receptor that is inhibited to indicate a decrease in the signaling by that receptor).  Note that when editing Event Components, clicking an existing Event Component from the Suggestions menu will autopopulate these fields, along with their source ID and description.  To clear any fields before submitting the event component, use the 'Clear process,' 'Clear object,' or 'Clear action' buttons.  If a desired term does not exist, a new term request may be made via Term Requests.  Event components may not be edited; to edit an event component, remove the existing event component and create a new one using the terms that you wish to add.  Further information on Event Components and Biological Context may be viewed on the attached pdf. More help
Process Object Action
sensory perception of sound decreased

Key Event Overview

AOPs Including This Key Event

All of the AOPs that are linked to this KE will automatically be listed in this subsection. This table can be particularly useful for derivation of AOP networks including the KE.Clicking on the name of the AOP will bring you to the individual page for that AOP. More help
AOP Name Role of event in AOP Point of Contact Author Status OECD Status
GSK3beta inactivation leads to increased mortality KeyEvent Vid Modic (send email) Open for citation & comment

Taxonomic Applicability

Latin or common names of a species or broader taxonomic grouping (e.g., class, order, family) that help to define the biological applicability domain of the KE.In many cases, individual species identified in these structured fields will be those for which the strongest evidence used in constructing the AOP was available in relation to this KE. More help
Term Scientific Term Evidence Link
Vertebrates Vertebrates NCBI
Invertebrates Invertebrates NCBI

Life Stages

An indication of the the relevant life stage(s) for this KE. More help

Sex Applicability

An indication of the the relevant sex for this KE. More help

Key Event Description

A description of the biological state being observed or measured, the biological compartment in which it is measured, and its general role in the biology should be provided. More help

Hearing refers to the ability to perceive sound vibrations propagated as pressure changes through a medium such as air or water. Reduced hearing in the context of this key event can refer to reduction in the perceived volume of a sound relative to the amplitude of sound waves. Reduced hearing may also refer to a reduced range of frequencies that can be perceived.

How It Is Measured or Detected

A description of the type(s) of measurements that can be employed to evaluate the KE and the relative level of scientific confidence in those measurements.These can range from citation of specific validated test guidelines, citation of specific methods published in the peer reviewed literature, or outlines of a general protocol or approach (e.g., a protein may be measured by ELISA). Do not provide detailed protocols. More help

Hearing is generally measured behaviorally or electrophysiologically.

  • Common behavioral tests involve transmission of pure tones of defined amplitude and frequency using and audiometer or PC and using a behavioral response (e.g., clicking a button; startle response) to determine whether the tone is perceived.

Electrophysiological tests:

  • Auditory brainstem response (ABR): Uses electrodes placed on the head to detect auditory evoked potentials from background electrical activity in the brain.

Hearing tests in Fish:

  • Through the mid-late 1980s conditioning and behavioral tests were most commonly employed in testing fish hearing. Methods reviewed by Fay (1988)
  • A high throughput behavioral test for detecting auditory response in fish has been described (Bang et al. 2002).
  • Invasive electrophysiological methods involving surgical insertion of electrodes into the auditory nerves have been employed.
  • Non-invasive recording of Auditory Evoked Potentials (AEPs; synonymous with ABRs) are now the most common approach for measuring hearing in fish. AEPs can be recorded via electrodes attached cutaneously to the head (see review by Ladich and Fay, 2013).

Domain of Applicability

A description of the scientific basis for the indicated domains of applicability and the WoE calls (if provided).  More help
  • A sense of hearing is known to exist in a wide range of vertebrates and invertebrates, although the organs and structures involved vary widely.


List of the literature that was cited for this KE description. More help
  • Fay RR (1988) Hearing in vertebrates: a psychophysics databook. Hill-Fay Associates, Winnetka, Ill
  • Ladich F, Fay RR. Auditory evoked potential audiometry in fish. Reviews in Fish Biology and Fisheries. 2013;23(3):317-364. doi:10.1007/s11160-012-9297-z.
  • Bang PI, Yelick PC, Malicki JJ, Sewell WF. High-throughput behavioral screening method for detecting auditory response defects in zebrafish. J Neurosci Methods. 2002 Aug 30;118(2):177-87. PubMed PMID: 12204308.