II. Background
- OTC Hearing Aids will be available in U.S. in 2023
III. Evaluation: Available Features When Purchasing a Hearing Aid
- Digital noise reduction (most modern Hearing Aids)
- Reduces Ambient common noises such as wind
-
Tinnitus Masking (most modern Hearing Aids)
- External noise volume adjusted to mask the specific Tinnitus frequency
- Feedback Suppression
- Prevents squealing sound (microphone feedback)
- Directional Microphones
- Sound directly in front of patient is amplified, and sounds from other directions are reduced
- Automatic noise level adjustments
- Newer Hearing Aids adjust volumes to optimize speech understanding given Ambient noise
- Multiple Pre-Programmed Settings
- Audiologist can setup multiple different modes for specific listening needs and environments
- Rechargeable Batteries
- No need to replace batteries (every 1-2 weeks, ~30 per year) eases maintenance (esp. low dexterity, Vision)
- Smartphone Integration
- Newer Hearing Aids connect to smartphones to adjust volumes and listening profiles via manufacturer apps
- Wireless or Bluetooth Connectivity
- Newer Hearing Aids may connect to phones, computers, televisions either directly or via secondary device
- Telecoil (T-Coil)
- T-Coil compatible devices (phones) and facilities (e.g. Hearing loop theaters) improve sound quality
IV. Types: Location
- Hearing Aid behind the ear (mild to severe Hearing Loss)
- Classic Hearing Aid with the electronics in a small case behind the ear
- Sound tube exits the Hearing Aid and is placed inside the ear
- Largest Hearing Aids, but easier to use, with volume control and some are rechargeable
- Mini Hearing Aid external and receiver in ear canal (mild to severe Hearing Loss)
- Ear canal receiver connects via a thin wire to a small Hearing Aid behind the ear
- Typically rechargable devices with many added modern features, and less visible than behind the ear
- Manual dexterity needed to position, and susceptible to earwax clogging
- Hearing Aid completely In the ear canal (mild to moderate Hearing Loss)
- Custom made Hearing Aid that completely sits within the ear canal (Least externally visible Hearing Aid)
- Batteries are small, with short lives, difficult to handle, and not rechargeable
- Lack added features (e.g. volume control, directional microphone, T-Coil) and susceptible to earwax clogging
- Full Ear including bowl/concha (moderate to severe Hearing Loss)
- Largest devices that are the easiest to manipulate by those with decreased dexterity
- Hearing Aid fills the external bowl of the ear (antihelix, concha) and canal
- Available as full shells or half shells (fill only part of the ear bowl)
V. Types: Conventional Analog Hearing Aids
- Cost: ~$900 per ear
- Components
- Battery
- Microphone transduces sound into electrical energy
- Receiver changes electrical energy into sound
- Most Hearing Aids can adjust volume
- May be a problem with background noise
- Sub-Types
- Linear (Simple Hearing Aid)
- Amplifies loud and soft sounds equally
- Non-Linear
- Varied amplification for loud and soft sounds
- Decreased recruitment (increased loudness)
- Linear (Simple Hearing Aid)
VI. Types: Programmable Hearing Aids
- Programmable by audiologist
- Sound levels adjustable for audibility and comfort
- Volume per frequency
- Intensity
- Microphone power output
- Compression Ratios
- Some available with multiple programs
- (e.g. telephone, music)
VII. Types: Digital Hearing Aids
- Cost: ~$2900 per ear
- Digital signal processor samples incoming signals
- Adjusts in different sound environments
- Can reduce background noise from non-speech source
- Enhances speech understanding
- Programmable by audiologist
- See Above
VIII. Management
- Hearing Aids amplify many sounds including background noise
- Expect a time to adjust to Hearing Aids, and tuning out background noise (e.g. footsteps)
- Proficiency with Hearing Aids requires a training period with frequent, continuous Hearing Aid use
- Start with less noisy
-
General measures
- Ears should be dry before inserting Hearing Aids
- Turn off Hearing Aids when not in use
- Removing ear wax with cotton swabs is not needed and may cause ear Trauma
- Remove Hearing Aids when sleeping, bathing, swimming, applying hair care products or instilling ear medications
- Light rain and mild sweating is not typically a problem
- Clean Hearing Aids daily with a soft cloth
- Button Batteries
- May need changing as every week or more
- Button batteries are dangerous if swallowed (keep away from pets and young children)
- Ear Pruritus or Irritation
- Causes
- Over-cleaning (e.g. wax removal decreases ear canal protection)
- Dry Skin
- Mal-fitting Hearing Aid
- Reaction to Hearing Aid material (uncommon)
- Approach
- Expect irritation and itching to improve over time
- Consider Skin Lubricant (skin Moisturizer) application overnight while Hearing Aids are out of the ear
- Recheck with Hearing Aid specialist if persists
- Causes
IX. Resources
- Hearing Aid Styles (Cleveland Clinic)
- Best Hearing Aids (NCOA)
X. References
- (2022) Presc Lett 29(9): 52
- Michels (2019) Am Fam Physician 100(2): 98-108 [PubMed]
- Unwin (2024) Am Fam Physician 109(3): 279-83 [PubMed]