1 / 12

Amplification/Sensory Systems

Amplification/Sensory Systems. SPA 4302 Summer 2007. Hearing Aid Development. thru the 1800s: Acoustic Devices Circa 1900: Carbon Devices 1930s: Vacuum Tube Devices 1950s: Transistor Devices 1980s: Digital Devices. Hearing Aid Circuit Overview. Analog :

aretha
Télécharger la présentation

Amplification/Sensory Systems

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Amplification/Sensory Systems SPA 4302 Summer 2007

  2. Hearing Aid Development • thru the 1800s: Acoustic Devices • Circa 1900: Carbon Devices • 1930s: Vacuum Tube Devices • 1950s: Transistor Devices • 1980s: Digital Devices

  3. Hearing Aid Circuit Overview • Analog: • mic – amp – filters – atten – receiver • Digital: • mic – AtoD – processing – DtoA – receiver • Compression: circuitry or programming to reduce the amplification of loud sounds to keep them below UCL • Tele-coil: direct pick up from a telephone’s electromagnetic field digital

  4. Characteristics of Hearing Aids • ________-: • Maximum output of aid • Acoustic Gain: • dB difference between output and input • __________________-: • range of frequencies amplified • shown as curve, and calculated • Distortion: • equivalent input noise • __________ distortion

  5. Binaural Amplification • Monaural fittings may permit auditory deprivation effects in the unaided ear • Binaurally fitted pts may show improved • listening in noise • localization • HOWEVER, • this has been difficult to document clinically • some (particularly elderly) pts will actually do worse with binaural than monaural fitting.

  6. Types of Hearing Aids • Digital/Analog/Hybrid • Behind the Ear • In the Ear • Canal • Completely in Canal • Bone conduction • Implanted

  7. Cochlear Implants • ____- Processor - electrodes • Electrical stim of neurons • via up to ___ electrodes • Latest generation of devices are successful with both post-and pre-lingually deafened pts.

  8. Selecting Hearing Aid Candidates • More than just the audiogram: • Expectations and Motivation • Communicative Demands • Vocation/Education/Financial Resources

  9. Dispensing Hearing Aids • An Historical/Hysterical Issue: • Audiologists are the persons best qualified to fit hearing aids.

  10. Selecting HAs for Adults • Ideal HA fitting should (Carhart, 1975): • Provide a restoration of adequate sensitivity for speech and environmental sounds too faint to hear without the hearing aids • Provide a restoration, retention, and or acquisition of the clarity (including intelligibility and recognition) of speech and other sounds within ordinary, relatively quiet environments • Achieve the same when these sounds are in noisier environments • Ensure that higher intensity sounds are not amplified to an intolerable level

  11. Verifying Hearing Aid Performance • Probe microphone “Real Ear” measurements • With hearing aid in place (in situ) • Without aid in (real ear unaided response) • Insertion loss: presence of aid in ear plugs it and alters the resonance of the pinna and canal.

  12. Hearing Assistance Technologies • _________________________ • Visual/Vibratory Alerting • FM/Infrared transmission • _________________

More Related