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Early Detection of Noise-Induced Hearing Loss

This study is currently recruiting participants. (see Contacts and Locations)
Verified November 2014 by Department of Veterans Affairs
Information provided by (Responsible Party):
Department of Veterans Affairs Identifier:
First received: November 25, 2009
Last updated: November 4, 2014
Last verified: November 2014

This study measures sounds produced by the sensory receptors of the inner ear called hair cells. These sounds are called otoacoustic emissions and one special case the investigators are studying are called distortion product otoacoustic emissions (DPOAEs) produced by presenting two tones to the ear. If the ear is damaged by noise exposure DPOAEs are reduced. In this study the investigators are attempting to improve the DPOAE test by adding a third tone to make the test more frequency specific. Whether the third tone helps will be determined by comparing DPOAEs collected with and without the third tone to clinical audiograms. If the addition of the third tone helps then the investigators expect DPOAEs tracked as a function of frequency (DP-grams) will more closely match the clinical audiograms.

Hearing Loss, Sensorineural

Study Type: Observational
Study Design: Observational Model: Case-Only
Time Perspective: Cross-Sectional
Official Title: Early Detection of Noise-Induced Hearing Loss

Resource links provided by NLM:

Further study details as provided by Department of Veterans Affairs:

Primary Outcome Measures:
  • DP-gram with interference tone 1/3 octave above f2 [ Time Frame: At the end of the testing session ] [ Designated as safety issue: No ]

Biospecimen Retention:   None Retained

No biospecimens will be collected for this study

Estimated Enrollment: 75
Study Start Date: January 2010
Estimated Study Completion Date: December 2015
Estimated Primary Completion Date: June 2015 (Final data collection date for primary outcome measure)
Group 1
Veterans with sensorineural hearing loss

Detailed Description:

The overall goal of the proposed research is to identify features of distortion product otoacoustic emissions (DPOAEs) that will eventually improve clinical methods for the early detection of noise-induced hearing loss (NIHL), which is a major sensory disability suffered by military veterans, in particular. Toward this end, a special-purpose DPOAE measure we call an augmented will be obtained. These DP-grams will test the notion that subtle post-noise changes in the DPOAE response space can be more sensitively identified when the f2 and basal source DPOAEs are isolated by the use of an interference tone (IT) and vector subtraction methods than by the commonly employed standard DP-gram procedures. The term 'augmented' maps or DP-grams was coined to describe these frequency functions when obtained with the IT present in that, under this condition, the basal source that 'fills in' or 'masks' the damage pattern is removed. The discovery of the contaminating basal source promises to modify the hearing field's current knowledge concerning the fundamental processes underlying DPOAE generation, and may also lead to the development of DPOAE tests that more sensitively identify the earliest stages of NIHL. Such tests may also be useful in veterans, who are clinic patients and often have significant preexisting hearing losses in that higher-level primary tones can be used to increase the signal-to-noise ratio (SNR) while maintaining their sensitivity and frequency specificity. We will test the ability of augmented DP-grams elicited by higher-level primary tones to uncover damaged regions in veterans with NIHL. The notion examined here is that high-level primary tones will be more useful under conditions of preexisting hearing loss than conventional low-level primaries using the optimized augmented DP-gram by removing basal sources that come into play to obscure damaged cochlear regions as primary-tone levels are increased. Together, the combined experiments will provide a more complete understanding of the generation of DPOAEs, which will permit the creation of a useful clinical test for diagnosing and monitoring the development of NIHL.


Ages Eligible for Study:   18 Years to 65 Years
Genders Eligible for Study:   Male
Accepts Healthy Volunteers:   Yes
Sampling Method:   Non-Probability Sample
Study Population

Veterans reporting to the VA Loma Linda Healthcare System identified with sensorineural hearing loss


Inclusion Criteria:

  • Veterans 18-65 years old

Exclusion Criteria:

  • Individuals with no measurable distortion-product otoacoustic emissions (DPOAEs) since the goal of the study is to relate DPOAEs to hearing function
  Contacts and Locations
Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the Contacts provided below. For general information, see Learn About Clinical Studies.

Please refer to this study by its identifier: NCT01022710

Contact: Barden B Stagner (909) 825-7084
Contact: Alisa Nelson-Miller (909) 825-7084

United States, California
VA Medical Center, Loma Linda Recruiting
Loma Linda, California, United States, 92357
Contact: Glen K Martin, PhD    909-825-7084 ext 3351   
Principal Investigator: Glen K. Martin, PhD         
Sponsors and Collaborators
Principal Investigator: Glen K. Martin, PhD VA Medical Center, Loma Linda
  More Information

Responsible Party: Department of Veterans Affairs Identifier: NCT01022710     History of Changes
Other Study ID Numbers: C7107-R, 00860
Study First Received: November 25, 2009
Last Updated: November 4, 2014
Health Authority: United States: Federal Government

Keywords provided by Department of Veterans Affairs:
hearing loss
otoacoustic emissions

Additional relevant MeSH terms:
Hearing Loss
Hearing Loss, Noise-Induced
Hearing Loss, Sensorineural
Ear Diseases
Hearing Disorders
Nervous System Diseases
Neurologic Manifestations
Otorhinolaryngologic Diseases
Sensation Disorders
Signs and Symptoms processed this record on November 24, 2014