Chapter 4 - Special Test Procedures
Delayed Auditory Feedback (DAF)
If a person’s voice is recorded and played back with a delay of 0.1 to 0.2 seconds, the
auditory feedback causes the speaker to slow down or alter his speech in a stuttering
manner.
1. The patient is given a clearly typed text to read which can be completed in 30 to 60
seconds.
2. Using patient earphones, or sound field speakers, the test may be performed by routing the
stimulus (Ext A) to both ears (Left/Right), and with or without Speech Noise to the non-test
ear.
3. The Examiner uses the same monitoring procedure described in Step 2 of the Lombard test.
4. The patient is placed before the talk back microphone and asked to read the text. His
reading is tape recorded and timed with the timer.
5. The patient is asked to repeat the reading while the recording of the speaker’s voice is
routed to the selected transducer with a delay of 0.1 to 0.2 seconds.
Note: A three head tape recorder with the appropriate delay capabilities is required.
6. The intensity of the signal (controlled by the attenuators) is first set to 0 dB HL and raised
10 dB after each reading is complete until a positive result is seen.
7. Each reading is timed with the timer. A change in the reading rate (3 to 5 seconds), an
increase in the vocal intensity, or a stuttering effect indicate that the auditory feedback was
heard.
4-9
1761-0100 Rev. B
To Next Page
Loading...
