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

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.

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.

• Device: The Hearing Laser
  Two 6-minute low level laser light applications to the head/neck/ears region, each one week apart.
• Device: Placebo Laser
  inactive low level laser light therapy with no therapeutic output

• Active Comparator: active low level laser light therapy
  Active low level laser light therapy of 635nm
  Intervention: Device: The Hearing Laser
• Placebo Comparator: inactive low level laser light therapy
  inactive low level laser light therapy with no therapeutic output
  Intervention: Device: Placebo Laser

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.