Bone-Anchored Hearing Implants

What are Bone-Anchored Hearing implants?

Bone-anchored hearing implants are not hearing aids. Instead, bone-anchored implant systems are a combination of a sound processor (worn behind the ear), a small connecting abutment and a small implanted titanium fixture implanted in the bone behind the ear. The system allows sound to be conducted through the bone of the skull directly to the inner ear (cochlea) rather than through the middle ear -- a process known as direct bone conduction. No component of bone-anchored implants fit inside the ear or ear canal. The bone-anchored hearing systems are approved by the Food and Drug Administration (FDA) as class II devices.

Parts of Bone-Anchored Implant Systems

The bone-anchored implant system is comprised of three parts -- a titanium fixture, a connecting abutment, and a detachable sound processor. Unlike hearing aids, the bone-anchored systems includes an implant -- the titanium fixture -- that osseointegrates (i.e. grows into bone) with living tissue to form a permanent, functional bond with the bone of the skull. During a minor outpatient surgical procedure, usually performed under local or "twilight" anesthesia, the titanium fixture is placed in the mastoid bone behind the ear.

How Many Bone-Anchored Implant Systems are Available?

There are currently two companies that make the bone-anchored implants. The BP 100 (now called the Baha 3) is made by the Cochlear Corporation and the Ponto Pro is made by Oticon Medical.

BP 100 Ponto Pro Bone-Anchored Hearing System
BP 100 (Now called the Baha 3) Bone-Anchored Implant System Ponto Pro Bone-Anchored Hearing System

 

How Does the Bone-Anchored Implant Work?

How Bone-Anchored Implant Works

1. A sound processor picks up sound vibrations.

2. The sound processor is attached to an abutment, which sits above the skin. The abutment transfers the sound vibrations from the processor to the titanium implant in the bone.

3. Since the small titanium implant is fused with the bone of the skull, the implant transfers the sound vibrations to the functioning inner ear (cochlea).

Who Can Benefit From a Bone-Anchored Implant?

Bone-anchored implants are approved for anyone over the age 5 years old for the the treatment of conductive or mixed hearing loss, as well as for unilateral sensorineural hearing loss, also known as Single Sided Deafness (SSD).

Prior to bone-anchored implants, patients with SSD had only one available treatment -- the CROS (contralateral routing of signal) hearing aid, a treatment with limited performance due to its placement inside the only functioning ear. For those with SSD, the bone-anchored implant gives patients the opportunity to perceive hearing as if the sound were coming from the deaf side.

For those under age five years old, there is a specially designed headband that holds the bone-anchored sound processor. The headband uses an adjustable elastic band to hold the sound processor comfortably against the skin without the abutment and fixture.

Examples of Specific Conditions Helped by Bone-Anchored Implants

  • Congenital absence of the ear canal (microtia)
  • Chronic ear drainage from outer or middle ear infection (since the bone-anchored device does not block the outer ear canal, as is true for hearing aids, which may be a cause for aggrevation of chronic ear drainage)
  • Otosclerosis in an only hearing ear
  • Single-sided deafness, regardless of the cause of hearing loss

 

For patients with Single-Sided Deafness AND a hearing loss in the opposite ear, a more powerful bone-anchored hearing device is recommended. The following table is summary of the Cochlear Corporation and Oticon Medical power options:

 

BAHA 3 Power

Ponto Pro Power

Manufacturer

Cochlear Americas

Oticon Medical

Fitting Range

Up to 55dBHL

Up to 55dBHL

Number of Channels

12

15

Number of Memories

3

4

Feedback Cancellation

Yes

Yes

Noise Reduction

Yes

Yes

Multiband Adaptive Directionality

Yes

Yes

Bone Conduction Measurement available in software

Yes

Yes

Tamper-Resistant Battery Door Available

Yes

Yes

T-coil Available

Yes

Yes

FM Compatible

Yes

Yes

Controls on Processor

Program Button and Volume Buttons

Program Button and Volume Wheel

Battery Size

675 Disposable

675 Disposable

Weight

19 grams with battery

17 grams without battery

Dimensions

36x22x12mm

34x21x11mm

Warranty

2 years

2 years

 

 

Baha 3 Power

Ponto Pro Power

Manufacturer

Cochlear Americas

Oticon Medical

Fitting Range

Up to 55 dB HL

Up to 55 dB HL

Number of Channels

12

15

Number of Memories

3

4

Feedback Cancellation

Yes

Yes

Noise Reduction

Yes

Yes

Multiband Adaptive Directionality

Yes

Yes

Bone Conduction Measurement Available in Software

Yes

Yes

Tamper-Resistant Battery Door Available

Yes

Yes

T-Coil Available

Yes

Yes

FM Compatible

Yes

Yes

Controls on Processor

Program Button and Volume Buttons

Program Button and Volume Wheel

Battery Size

675 Disposable

675 Disposable

Weight

19 grams with battery

17 grams without battery