|
Since the dB HL
scale dramatically simplifies the interpretation of pure tone threshold
results, it has become the standard for reporting pure tone thresholds
in the United States. In fact, a widely accepted document exists which
precisely defines reference values (i.e., 0 dB HL) for each test frequency.
The values specified in this document are the ones we used for the last
few examples and are shown below. (The actual reference values that define
0 dB HL will change depending on the type of headphone or speaker used
to present the test tone to the patient. The values reported below are
to used with headphones referred to as TDH-49 or TDH-50 which are, by
far, the most commonly used headphones.)
| Frequency (Hz.) |
125
|
250
|
500
|
1000
|
2000
|
3000
|
4000
|
6000
|
8000
|
|
TDH 49,5
|
47.5
|
26.5
|
13.5
|
7.5
|
11.0
|
9.5
|
10.5
|
13.5
|
13.0
|
|
