The Effect of Low-Level Laser Stimulation on Hearing Thresholds

April 26, 2017 updated by: Shawn Goodman, University of Iowa
The purpose of this study is to determine whether low-level laser therapy can improve hearing thresholds in individuals with hearing loss. Subjects will be randomly assigned to a treatment, placebo, or control group. The treatment group will be given a three treatment of low-level laser therapy, which consists of shining low-level lasers beams onto the ear and head. The laser beams are cool to the touch, and do not cause discomfort. Each laser treatment will last approximately 4 minutes. Three treatments will be applied three times within the course of one week. Hearing tests will be administered immediately before treatment, immediately after treatment, and six weeks after treatment. Results will be analyzed to determine the effect of the laser treatment on hearing.

Study Overview

Status

Terminated

Conditions

Intervention / Treatment

Detailed Description

Low-level laser therapy has been practiced for about 20 years in Europe and is beginning to be practiced in the US. Theoretically, laser energy in the red and near infrared light spectrum is capable of penetrating 2-5 cm into tissue and can stimulate mitochondria in the cells to produce more energy (through the production of adenosine triphosphate), which in turn may help prevent or repair tissue damage. The effects of low-level laser therapy on hearing have not been well studied. It has been suggested that laser therapy might help repair damage to the cochlea and restore some degree of hearing loss. Studies of low-level laser stimulation of cochleae utilizing microscopy, PET imaging, and MRI suggest potential therapeutic benefit to hearing. While preliminary studies suggest a possible improvement in hearing thresholds, a carefully controlled study is needed to verify the results using a valid battery of audiological tests.

Study Type

Interventional

Enrollment (Actual)

35

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • United States
    • Iowa
      • Iowa City, Iowa, United States, 52242
        • University of Iowa

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

18 years to 75 years (Adult, Older Adult)

Accepts Healthy Volunteers

No

Genders Eligible for Study

All

Description

Inclusion Criteria:

  • bilateral sensorineural hearing loss
  • normal middle ear status

Exclusion Criteria:

  • pregnant or lactating
  • serious mental health illness or medical/psychiatric hospitalization
  • treatment with cancer chemotherapeutic agents or aminoglycoside antibiotics
  • taking Aspirin, Ibuprofen, Naprosyn, Aleve
  • taking any Quinine-related drugs
  • taking any loop diuretics
  • have a developmental disability or cognitive impairment
  • history of drug abuse
  • involved in litigation or claim related to hearing loss
  • regularly exposed to significant occupational or recreational noise
  • have a photosensitivity disorder
  • have a retinal disease

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Triple

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: Low-Level Laser Therapy
Low-level laser applied for approximately 4 minutes to the area around the pinna, the back of the neck, and the top of the head.
Radiation: Low-level Laser Therapy
Portable unit containing two laser diodes producing 532 and 635 nm wavelengths. Both diodes produced energy levels of 7.5 mw (class IIIb). Beams from both diodes were dispersed through lenses to create parallel line-generated beams, rather than spots. The 532 nm light was constant, and the 635 nm light was pulsed, with frequencies of 15 and 33 Hz. The pulsing alternated between frequencies every 30 seconds.
Other Names:
  • Erchonia EHL laser (Erchonia Medical, Inc.)
Placebo Comparator: Disabled Laser
Low-level laser device with laser diodes disabled. Also applied for approximately 4 minutes to the area around the pinna, the back of the neck, and the top of the head.
Other: Placebo Comparator: Disabled Laser
Portable unit containing two DISABLED laser diodes. Same protocol was followed as for the Experimental (radiation) group, except that the disabled diodes produced no radiation.
No Intervention: Control
Visit laboratory using same schedule as experiment and placebo. No Low-level laser or any treatment applied. Used to assess normal test-retest variability.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Change in Speech Perception
Time Frame: 7-10 days after baseline measures recorded
Hearing status, as assessed by the Connected Sentence Test (CST). Difference scores (post-test - pretest) are reported. The CST approximates everyday conversation. Scoring is based on the number of correctly repeated key words. Higher numbers indicate better scores. The minimum score is 0 (0%) and the maximum is 100 (100%). When comparing test-retest scores for an individual, Cox et al. (1988) suggest that changes of 15% or more (based on 100 key words) are indicative of significant changes. We subtracted the post-test from the pre-test, so that negative difference scores indicate worse performance, and positive difference scores indicate better performance. Difference scores with an absolute value smaller than 15 are interpreted as no significant change. In addition, pre- and post-test performance was assessed for groups using t-tests on the difference scores.
7-10 days after baseline measures recorded

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

University of Iowa

Collaborators

GN Resound

Investigators

  • Principal Investigator: Shawn S Goodman, PhD, University of Iowa

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start

September 1, 2009

Primary Completion (Actual)

December 1, 2009

Study Completion (Actual)

December 1, 2009

Study Registration Dates

First Submitted

March 25, 2013

First Submitted That Met QC Criteria

March 25, 2013

First Posted (Estimate)

March 28, 2013

Study Record Updates

Last Update Posted (Actual)

June 1, 2017

Last Update Submitted That Met QC Criteria

April 26, 2017

Last Verified

April 1, 2017

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • 200808718

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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