Prescriptions Flashcards
Linear Prescriptions
Shapiro, Pogo, NAL, NAL-R, DSL, MSU, Burger, CID
List the Non-Liner Prescriptions
NAL-NL1, NAL-NL2, DSLm[i/o], DSL[i/o], CAMREST, CAM2, CAMEQ, FIG6, LGOB,IHAFF/contour, ScaleAdapt
Prescriptions based on Threshold
NAL, NAL-R, NAL-NL1, NAL-NL2, CAMREST, CAM2, CAMEQ, FIG 6, POGO, Burger
Prescription based on loundnes
IHaff/contour, ScaleAdapt, CID, Shapiro, LGOB, DSL[i/o]-curvilinear
Prescriptions based on both thresholds and Loundness
MSU, DSL[i/o], DSLm[i/o]
Prescription based on loudness normalizations (thresholds)
CAMREST, Fig6, DSLm[i/o], DSL[i/o]
Prescriptions based on loudness normalizations (scaling)
ScaleAdapt, IHaff, LGOB
Prescriptions based on loudness equalization
CAM2,CAMEQ
Prescriptions based on intelligibility maximization
NAL, NAL-R, NAL-NL1, NAL-NL2
POGO - Prescription of gain and output
A linear prescription based on thresholds using the half gain rule with an additional low-cut
LGOB - Loudness growth in half octave bands
A non-linear prescription, based on loudness normalization. It uses a 7 point scaling method.
IHAFF/Contour - Independent hearing aid fitting forum
A non-linear prescription based on loudness normalization using a scaling method
Fig6
A non-linear prescription that uses data across a large number of people with similar degrees of threshold (Loudness normalization -threshold)
CAMREST - Cambridge restoration of loudness
A non-linear prescription based on thresholds. It normalizes loudness - threshold. A more sophisticated version of NAL-NL1 and NAL-NL2
CAMEQ - Cambridge Loudness Equalization
A non-linear prescription based on thresholds. It uses a loudness equalization formula
CAMEQ2-HF/ CAM2 - Cambridge loudness equalization high frequency
A non-linear prescription that equalizes loudness using thresholds up to 10 kHz
NAL - National acoustic laboratories of Australia
A linear prescription aimed to maximize speech intelligibility at the listening level preferred by the aid wearer. Based on thresholds and the half gain rule
NAL - NL 1 & 2
A non-linear prescription aimed to maximize speech intelligibility based on thresholds. Takes into account dead zones
DSL - Desired sensation level
A linear prescription that provides an audible comfortable signal at each frequency region. Uses REAR
DSL[i/o]
Non- linear prescriptions that normalize loudness across frequencies. They are based on both loudness and thresholds.
DSL[i/o] - linear uses WDRC
DSL[i/o] - Curvilinear normalizes loudness
DSLm[i/o] - Multistage
Limits at the highest levels
WDRC at mid-levels
Linear amplification below compression thresholds (optional expansion)
NAL vs. DSL (non- linear prescriptions)
Fundamental principle
NAL maximizes speech intelligibility
DSL is a threshold based loudness normalization prescription, maximizing audibility
NAL Vs. DSL (non-linear prescriptions)
Over all average gain
NAL prescribes less average gain over all
DSL prescribes higher average gain, more than is preferred by adults
NAL Vs. DSL (non-linear prescriptions)
Language
NAL takes into account patients that speak tonal languages
DSL does not take this into account
NAL Vs. DSL (non-linear prescriptions)
Compression
NAL - The compression threshold prescribed is based on speech at an overall level of 52 dB SPL
DSL[i/o]- linear –prescribes a greater compression ratio than that required to normalize loudness. DSL uses low compression thresholds so that all speech can be within compression region
NAL Vs. DSL (non-linear prescriptions)
Dead regions
NAL takes into account dead regions, does not amplify much in that region since the is little benefit
DSL does not take dead regions into account
NAL Vs. DSL (non-linear prescriptions)
Maximum Power Output (MPO)
NAL finds the LDL based on the threshold, and the point at which speech starts to clip. MPO is placed between these two levels
DSL takes into account loudness summation across frequency and the crest factor of speech is specified for broadband signals
NAL Vs. DSL (non-linear prescriptions)
User experience
NAL takes into account new users vs. experienced users
DSL does not offer a correction for user experience
NAL Vs. DSL (non-linear prescriptions)
Gender Differences
NAL takes gender into account, males get more gain than females
DSL does not take gender into account
NAL Vs. DSL (non-linear prescriptions)
LDL
NAL does not allow patient specific information to be enter to change he LDL
DSL allows the audiologist to enter patient specific loudness discomfort levels
