Noise Stimulus
The uniformity of the spectrum level of acoustic pressure for the noise signal over 20
averages measured acoustically within their respective band limits will be:
±10 dB for insert or probe type earphones
±5 dB for supra-aural type earphones
Noise Band Widths:
Low Band: 125 -1600 Hz
High Band: 1600 - 4000 Hz
Broad Band: 125 - 4000 Hz (Relative to level at 1 kHz)
Band-edges accurate to within ±15%
Roll off rate: >12 dB/Octave
Stimulus Level Control
Tone Stimulus: The transfer of reference equivalent threshold values are based on the
article; “Reference Threshold Levels For The ER-3A Insert Phone”, by Laura Ann
Wilber, Barbara A. Krueger and Mead C. Killion, J. Acoustic Soc.
Am
.
Suppl
. 1, Vol.
81 Spring 1987. GSI determined the transfer data from an IEC 711 coupler to an
ANSI HA-1 coupler. Using this data, the reference threshold values were deter-
mined for both the Ipsi and Contra insert earphones for calibration in an ANSI HA-1
2cc coupler.
Noise Stimulus: The transfer of reference threshold values was done by GSI using the
“Threshold Determination Method.”
The transfer data from an IEC 711 to an ANSI
HA- 1 coupler was determined by GSI.
GSI TympStar Version 1 and Version 2 Service Manual 2 - 3
Specifications
Pressure Maximum Limits: -800 daPa to +600 daPa
Programmed Pressure Ranges:
Normal: + 200 to - 400 daPa
Wide: + 400 to - 600 daPa
Pressure Accuracy: ±10% or ±10 daPa, whichever is greater in cavities
from 0.5 cc to 5.0 cc.
Pressure Sweep Rate: 12.5 daPa/sec
50 daPa/sec
600/200 daPa/sec
Manual Sweep Rate Limit: 600 daPa/sec
Sweep Rate Accuracy: ±10%
Pressure System Leak Rate: < 1. 0 daPa/sec
(Measured at -600 and +400 daPa, while pressure servo is disabled.)
Pure Tone Stimulus
Frequencies for Contra phone and for Ipsi phone with time multiplexed
stimulus
. See Table 3.
Frequency Accuracy: ±3%
Total Harmonic Distortion :
< 5% at 500 Hz, 85dBHL
< 5% at 1000Hz - 3000Hz, 100dBHL
< 5% at 4000Hz, 75dBHL
< 10% at the maximum dBHL settings
To Next Page
Loading...
Need help?
General
