Moisture Related Failures Cause, Effect, Solution Daniel R. Schumaier, Ph.D. Ear Technology...

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Moisture Related Failures Cause, Effect, Solution Daniel R. Schumaier, Ph.D. Ear Technology Corporation

Transcript of Moisture Related Failures Cause, Effect, Solution Daniel R. Schumaier, Ph.D. Ear Technology...

Page 1: Moisture Related Failures Cause, Effect, Solution Daniel R. Schumaier, Ph.D. Ear Technology Corporation.

Moisture Related Failures

Moisture Related Failures

Cause, Effect, Solution

Daniel R. Schumaier, Ph.D.

Ear Technology Corporation

Page 2: Moisture Related Failures Cause, Effect, Solution Daniel R. Schumaier, Ph.D. Ear Technology Corporation.

We Deal With the Effects of Moisture on

Hearing Aids Every Day

We Deal With the Effects of Moisture on

Hearing Aids Every Day

Corrosion

Switch Problems

Microphone & Speaker Failure

Distortion

Loss of Clarity

Page 3: Moisture Related Failures Cause, Effect, Solution Daniel R. Schumaier, Ph.D. Ear Technology Corporation.

Causes of Moisture in Hearing Aids

Causes of Moisture in Hearing Aids

Accidents or Negligence

Cerumen

Perspiration

Environmental Conditions (Condensation) Temperature Humidity

Page 4: Moisture Related Failures Cause, Effect, Solution Daniel R. Schumaier, Ph.D. Ear Technology Corporation.

Previous StudiesPrevious Studies 1967, Bruner & House: found RH in

external ear canal always above 60%.

1996, Bailey & Valente: study done for Eveready Battery Co. to determine effect of humidity and temperature on zinc-air battery life. In-vivo studies, majority done at ambient temperature of 60-80 degrees F & RH below 50%.

Page 5: Moisture Related Failures Cause, Effect, Solution Daniel R. Schumaier, Ph.D. Ear Technology Corporation.

1999, Agnew (AAS presentation in 4/99): custom ITE worn in right ear, 100 measurements across USA, found that ambient RH and the RH inside the ITE tracked more closely than expected. Therefore, the operating environment inside an ITE was not as extreme as previously assumed.

Nevertheless, moisture causes a huge non-recoverable monetary loss to the industry, and loss of patient satisfaction that ultimately impacts sales.

Page 6: Moisture Related Failures Cause, Effect, Solution Daniel R. Schumaier, Ph.D. Ear Technology Corporation.

Relative HumidityRelative Humidity

The ratio of the quantity of water vapor actually present in the air to the quantity that would saturate the air at the existing temperature:

RH = p / psat X 100%

“Relative” means relative to temperature. Warm air holds more moisture than cold air. As the

temperature drops, condensation chances go up.

Page 7: Moisture Related Failures Cause, Effect, Solution Daniel R. Schumaier, Ph.D. Ear Technology Corporation.

Dew PointDew PointThe temperature at which the air can

not hold additional moisture at any given temperature (saturated).

Further decrease in temperature will result in condensation.

Page 8: Moisture Related Failures Cause, Effect, Solution Daniel R. Schumaier, Ph.D. Ear Technology Corporation.

Condensation ExampleCondensation ExampleWeather Report:

Relative Humidity: 60%Temperature: 90 F

Complicated formula, but in this case the Dew Point is 75 degrees F.

It means that condensation will be formed in the hearing aid even before the hearing aids reach room temperature.

Page 9: Moisture Related Failures Cause, Effect, Solution Daniel R. Schumaier, Ph.D. Ear Technology Corporation.

What Do Arizona & Alaska Have in

Common?

What Do Arizona & Alaska Have in

Common?

?Extreme Temperature Changes that Promote

Condensation

Page 10: Moisture Related Failures Cause, Effect, Solution Daniel R. Schumaier, Ph.D. Ear Technology Corporation.

What is Needed to Remove Moisture from

Hearing Aids?

What is Needed to Remove Moisture from

Hearing Aids?

Controlled Amount of Heat

Breaks surface tension – smaller drops

Reduces capillary pull (receiver tube)

Reduces the “Glue Effect”

Page 11: Moisture Related Failures Cause, Effect, Solution Daniel R. Schumaier, Ph.D. Ear Technology Corporation.

II. Moving Air II. Moving Air

Air circulation initiates natural diffusion effect (wet to dry).

Without controlled airflow, vaporized moisture will re-condense when temperature drops below dew point.

Active systems cause moisture to move out of the hearing aid. Passive systems don’t – except by random chance.

Closed Containers (Hearing Aids) are Difficult to Dry

Page 12: Moisture Related Failures Cause, Effect, Solution Daniel R. Schumaier, Ph.D. Ear Technology Corporation.

III. Charged Desiccant

A desiccant is a substance with high affinity for moisture molecules.

Moisture released from the hearing aid must be physically removed, otherwise it will redeposit/condense elsewhere.

Desiccant efficiency is temperature dependent.

Page 13: Moisture Related Failures Cause, Effect, Solution Daniel R. Schumaier, Ph.D. Ear Technology Corporation.

Why Not Just Heat the Aid?Why Not Just Heat the Aid?

Heat alone without moisture removal can create a “corrosive soup.”

Warm a small amount of water in a covered pan. When the pan cools, water inside recondenses when the temperature drops through the dew point, dripping off the lid when it is removed.

Page 14: Moisture Related Failures Cause, Effect, Solution Daniel R. Schumaier, Ph.D. Ear Technology Corporation.

ConclusionConclusion

Heat (controlled amount)

Moving Air (circulating around the aids)

Desiccant (moisture released must be adsorbed)

3 Things Necessary to Dry a Hearing Aid

Page 15: Moisture Related Failures Cause, Effect, Solution Daniel R. Schumaier, Ph.D. Ear Technology Corporation.

Solution: Dry & StoreHearing Aid Conditioning System Three patents Only product to

combine the three needed technologies for drying closed containers

UV light that reduces or ends itching ears or recurring otitis externa

Page 16: Moisture Related Failures Cause, Effect, Solution Daniel R. Schumaier, Ph.D. Ear Technology Corporation.

“Dry & Store has greatly improved the quality of my son’s life in the summertime. He was constantly having to get his hearing aids cleaned or repaired because of sweat damage. Thank you! Thank you! Thank you!” F.B., Georgia

“An exceptionally fine product that exceeds the claims made for it.” W.N.C., Florida

Page 17: Moisture Related Failures Cause, Effect, Solution Daniel R. Schumaier, Ph.D. Ear Technology Corporation.

“…the unit [Dry & Store] was the key to my feeling comfortable with wearing hearing aids in that it provides a wonderful sanitary place for overnight storage plus the added benefit of drying any wax present to dust… Excellent!” C.S. Brien, Maine

“My aids would be lost withoutDry & Store.” S.L., Athens, Georgia

Page 18: Moisture Related Failures Cause, Effect, Solution Daniel R. Schumaier, Ph.D. Ear Technology Corporation.

User Survey Results (5/99)

77% said their hearing aids sounded better.

72% said itching or recurring infections were eliminated or reduced.

54% said batteries lasted longer. 67% said need for repair was

eliminated or reduced. AND…

Page 19: Moisture Related Failures Cause, Effect, Solution Daniel R. Schumaier, Ph.D. Ear Technology Corporation.

The Bottom Line…The Bottom Line…

98% of regular Dry & Store users said they were satisfied!

(64.6% said “outstanding”or “very satisfied”)