Hearing Aid

Aka: Hearing Aid

1. See Also
   1. Hearing Loss
   2. Sensorineural Heaing Loss
   3. Presbycusis
   4. Home Adaptations for the Elderly
2. Types: Location
   1. Hearing Aid behind the ear
      1. Classic Hearing Aid with the electronics in a small case behind the ear
      2. Sound tube exits the Hearing Aid and is placed inside the ear
   2. Hearing Aid receiver in canal
      1. Receiver moved from within case, to within the ear
      2. Receiver connects to Hearing Aid via thin wire
   3. Hearing Aid completely In the ear
      1. Custom made Hearing Aid that completely sits within the ear canal
3. Types: Conventional analog Hearing Aids
   1. Cost: ~$900 per ear
   2. Components
      1. Battery
      2. Microphone transduces sound into electrical energy
      3. Receiver changes electrical energy into sound
      4. Most Hearing Aids can adjust volume
         1. May be a problem with background noise
   3. Sub-Types
      1. Linear (Simple Hearing Aid)
         1. Amplifies loud and soft sounds equally
      2. Non-Linear
         1. Varied amplification for loud and soft sounds
         2. Decreased recruitment (increased loudness)
4. Types: Programmable Hearing Aids
   1. Programmable by audiologist
      1. Sound levels adjustable for audibility and comfort
      2. Volume per frequency
      3. Intensity
      4. Microphone power output
      5. Compression Ratios
   2. Some available with multiple programs
      1. (e.g. telephone, music)
5. Types: Digital Hearing Aids
   1. Cost: ~$2900 per ear
   2. Digital signal processor samples incoming signals
   3. Adjusts in different sound environs
      1. Can reduce background noise from non-speech source
      2. Enhances speech understanding
   4. Programmable by audiologist
      1. See Above
6. References
   1. Michels (2019) Am Fam Physician 100(2): 98-108 [PubMed]