HP RM500SL - Manual (Page 97)

0611 RM500SL User’s Guide Version 2.8 Page 97
REUG, Real-Ear Unaided Gain , difference, in dB as a function of frequency, between the SPL (or
BSPL) at a specified measurement point in the ear canal and the SPL (or BSPL) at a field reference point,
for a specified sound field, with the ear unoccluded (ANSI S3.46).
REUR, Real-Ear Unaided Response, SPL (or BSPL), as a function of frequency, at a specified
measurement point in the ear canal, for a specified sound field, with the ear canal unoccluded (ANSI
S3.46).
Reference microphone, microphone used to measure the stimulus level in the measurement process or
to control it in the equalization process.
Release Time, the time required for HA output to fall to within +/-4dB of its steady-state level for an input
step from 90 to 55dB SPL. (ANSI S3.22)
REM, Real-Ear Measurement.
RTG, Reference Test Gain, the HFA gain for a 60 dB input SPL with the gain control at RTS (ANSI
S3.22).
Reference, Sound-field, the calibration point of a sound-field measurement.
RTS, Reference Test Setting of the gain control, for a 60 dB input SPL, the setting of the gain control
required to produce an HFA gain within 1.5 dB of the HFA-OSPL90 minus 17 dB. If the full-on HFA gain is
less than the HFA-OSPL90 minus 17 dB, the RTS is the full-on setting of the gain control (ANSI S3.22).
RSETS, Relative Simulated Equivalent Telephone Sensitivity, difference in dB between the HFA-
SPLITS (SPA-SPLITS) and the RTG plus 60 in the ‘M’ (microphone) mode. RSETS = HFA-SPLITS -
(RTG+60)
Saturation, in a hearing aid, the limiting of output caused by the output circuitry and transducer reaching
their maximum capability.
SPA, Special Purpose Average, the average of values in dB at three third octave frequencies separated
by 2/3 of an octave (ANSI S3.22). See also HFA.
Spectrum, the BSPL as a function of frequency for a broad-band signal.
SII, Speech Intelligibility Index, a quantity calculated from measures of speech, noise and hearing
threshold that is highly correlated with the intelligibility of speech (ANSI S3.5).
Speech Region, a statistical range of short-term spectra present in a speech passage. The short-term
spectra are typically 120 - 130 millisecond averages in 1/3 octaves. The statistical range is typically from
the 70
th
to the 99
th
percentile.
SPL, Sound Pressure Level, rms sound pressure relative to 20 uPa, expressed in decibels. SPL =
20log
10
(rms sound pressure / 20uPa).
SPLITS, coupler SPL for an inductive telephone simulator, SPL developed in a 2cc coupler by a
hearing aid with the gain control at the RTS when the input is the magnetic field generated by a TMFS
(ANSI S3.22).
TMFS, Telephone magnetic-field simulator, a device for producing a magnetic field of consistent level
and geometric shape when driven by a specified current (ANSI S3.22).
THD, Total Harmonic Distortion, the rms value of all harmonic components as a percentage of the rms
value of the fundamental. If less than 20%, the rms value of the total signal may be used instead of the
fundamental. For most hearing aids, the inclusion of harmonics above the third will not significantly alter
the THD (ANSI S3.22).
Transducer, a device which transforms energy from one form to another. For example, a microphone or
earphone.
UCL, Uncomfortable Listening Level, the level for a specified stimulus that is judged to be definitely
uncomfortable.