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Study of Low Level Laser Therapy and Word Recognition in Hearing Impaired Individuals

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details. Identifier: NCT00787189
Recruitment Status : Completed
First Posted : November 7, 2008
Results First Posted : July 11, 2011
Last Update Posted : February 10, 2020
Information provided by (Responsible Party):
Erchonia Corporation

Brief Summary:
The purpose of this clinical study is to determine the effectiveness of low level laser light therapy when applied around the head and ears in improving unaided word recognition in ears with sensorineural hearing loss.

Condition or disease Intervention/treatment Phase
Sensorineural Hearing Loss Device: The Hearing Laser Device: Placebo Laser Not Applicable

Detailed Description:
Sensorineural hearing loss accounts for about 90% of all hearing loss and is found in 23% of individuals older than 65 years. Sensorineural hearing loss occurs when the hair cells of the inner ear and the neural pathways to the auditory cortex are damaged. In most cases, sensorineural hearing loss cannot be improved, reversed or 'cured.' Current treatment options focus on methods that amplify external sounds and on teaching the patient various strategies to 'retrain' the brain to interpret external stimuli. Low Level Laser Therapy was first applied for the treatment of inner ear diseases by Uwe Witt, MD of Hamburg, Germany in the 1980's. Hearing impaired patients have inflammation and/or atrophy of the tissues and neural pathways connected to and supporting the cochlea's cilia hair structure, the hearing mechanism of the inner ear. Low level laser therapy is believed to stimulate the mitochondria of the adipocyte cells, which subsequently increases the production of ATP. The resultant surge in ATP production works to repair damaged tissue and regenerate cells reversing some of the damage incurred to the cochlea and thus improving aspects of hearing function.

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Study Type : Interventional  (Clinical Trial)
Actual Enrollment : 80 participants
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Triple (Participant, Investigator, Outcomes Assessor)
Primary Purpose: Treatment
Official Title: The Effects of the Erchonia Hearing Laser on Word Recognition in Hearing Impaired Individuals Clinical Study Protocol
Study Start Date : August 2007
Actual Primary Completion Date : June 2008
Actual Study Completion Date : June 2008

Resource links provided by the National Library of Medicine

Arm Intervention/treatment
Active Comparator: The Hearing Laser
Active low level laser light therapy of 635 nanometers (nm)
Device: The Hearing Laser
Two 6-minute low level laser light applications to the head/neck/ears region, each one week apart.

Placebo Comparator: Placebo Laser
inactive low level laser light therapy with no therapeutic output
Device: Placebo Laser
inactive low level laser light therapy with no therapeutic output

Primary Outcome Measures :
  1. Participants Whose Change in Percent Correct Word Recognition Scores From Baseline to One Week After Study Treatment Equalled or Exceeded the Minimum Change in a Reference Chart. [ Time Frame: baseline and one week ]
    Participants were asked to repeat 50 words presented one at a time through headphones to each ear separately at a comfortable listening level to the participant. The 50 words were from a phonetically-balanced list of monosyllabic words called the Central Institute for the Deaf (CID) W-22 lists. For each ear, each word repeated correctly was scored '1'. The total number correct for each ear was summed and multiplied by 2 to attain the percent of total words repeated correctly for each ear. The change in this percent from baseline to one week after study treatment was referenced against a chart. If the change was equal to or greater than the corresponding value in the chart, the participant was considered to have a successful study outcome.

Information from the National Library of Medicine

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Ages Eligible for Study:   18 Years and older   (Adult, Older Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   Yes

Inclusion Criteria:

  • Sensorineural hearing loss.
  • Mild or greater degree.
  • Adult onset.
  • Gradual onset.
  • Hearing loss stable over past 12 months.
  • Etiology of presbyacusis or noise-induced hearing loss.
  • Unaided word recognition score between 28% and 86%.
  • English as primary spoken language.
  • Willing and able to abstain from other treatments or medications to improve hearing ability.
  • Willing and able to abstain from work or other activities that involve loud noise exposure.

Exclusion Criteria:

  • Central auditory processing disorder.
  • Active/recurrent middle ear infection.
  • Meniere's disease.
  • Tympanic membrane perforation/tubes.
  • Cochlear implant.
  • Removal of acoustic neuroma.
  • Hyperacusis/misphonia.
  • Photosensitivity disorder.
  • Active infection/wound in head/ear region.
  • Pregnant/lactating.
  • Serious mental health illness.
  • Significant developmental disability/cognitive impairment.
  • History of drug/alcohol abuse.
  • Involvement in litigation/worker's compensation/disability benefits for hearing loss.
  • Other research participation in past 90 days.
  • Use of ototoxic medications known to cause temporary or permanent hearing loss.

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its identifier (NCT number): NCT00787189

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United States, California
McDonald Hearing Centers
Sacramento, California, United States, 95818
Sponsors and Collaborators
Erchonia Corporation
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Principal Investigator: Betty McNamara, M.S., CCC-A Maryjane Rees Language Speech & Hearing Center
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Responsible Party: Erchonia Corporation Identifier: NCT00787189    
Other Study ID Numbers: EHL-001
First Posted: November 7, 2008    Key Record Dates
Results First Posted: July 11, 2011
Last Update Posted: February 10, 2020
Last Verified: January 2020
Keywords provided by Erchonia Corporation:
sensorineural hearing loss
word recognition
Additional relevant MeSH terms:
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Hearing Loss
Hearing Loss, Sensorineural
Hearing Disorders
Ear Diseases
Otorhinolaryngologic Diseases
Sensation Disorders
Neurologic Manifestations
Nervous System Diseases