1 / 5

What if cross-hearing is a problem?

What if cross-hearing is a problem?. Necessary to prevent NTE from responding. Procedure: MASKING. Types of masking: Central versus peripheral Central masking: Elevation of threshold of a pure tone presented to one ear when noise is presented to the other ear. Around 5 dB threshold shift.

whitejeffrey
Download Presentation

What if cross-hearing is a problem?

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. What if cross-hearing is a problem? • Necessary to prevent NTE from responding. • Procedure: MASKING. • Types of masking: Central versus peripheral • Central masking: Elevation of threshold of a pure tone presented to one ear when noise is presented to the other ear. Around 5 dB threshold shift. • What types of maskers? Noise (white versus narrow).

  2. Effective masking (EM) • Amount of threshold shift provided by a certain amount of noise. • 20 dB EM is the amount of noise just enough to make a 20 dB HL 1000 Hz tone inaudible. • A 25 dB HL tone would be audible in the presence of 20 dB EM noise.

  3. Methods for masking • ‘Shotgun’ method • Minimum noise method: Use effective masking level in the non-test ear. Just enough noise to shift AC and BC thresholds in the non-test ear by 5 dB. • Maximum masking: BCTE + IA – 5 • Danger of overmasking, where masking level exceeds BCTE + IA – 5

  4. Hood’s plateau method • Measure unmasked threshold in test ear. • Present noise to non-test ear, starting at effective masking level. • Present tone. Test-ear threshold will probably go up. WHY? • If the tone is heard, then increase masking noise level in 5 dB steps till tone is not heard. • If the tone is not heard, then increase tone level till it becomes audible again. • At some point, tone will be heard even after masking noise level has increased several steps: PLATEAU • This is the masked threshold of the test ear.

  5. Minimum masking Maximum masking Sufficient masking Overmasking Undermasking

More Related