# Note: We decided not to use this approach!

#
Generic Curve Flags

The first two words of each curve frame contains the curve frame flags (flags 0 and 1). These flags contain information on the curve type, details about how the curve was measured or calculated, and other important data. To decipher the curve frame flags, the curve frame format must first be determined.

## Curve Frame Format (Flag 0, Bits 10-12)

Bits 10-12 of flag 0 contain the curve frame format:

Value | Description | Data Points
4 | Generic | Variable

Data Length

The number of data points in a generic curve is the packet length minus 9. (Or in header word 5 highest value)

## Source Type (Flag 1 Bit 6, Flag 1 Bit 4, Flag 1 Bit 3, Flag 0 Bit 0)

These four non-contiguous bits of data contain the source type used in the curve.

Value | Description
0 | Pure-tone
1 | Composite
2 | Fast pure-tone with warble (FP35 only)
5 | Composite chirp
8 | Pure tone burst/pulse
9 | Digital speech
11 | Distortion chirp
15 | Unknown source

## Correction Factors (Flag 1 Bit 7, Flag 1 Bit 0, Flag 0 Bit 3) [coupler type? Are there any non-coupler correction factors?] head mic effects?

These three non-contiguous bits of data represent the software correction factors used with the curve.

Value | Description
0 | No corrections
2 | OES corrections
4 | CIC corrections

## Reference microphone status (Flag 0, Bit 4)

Bit 4 of flag 0 indicates whether the reference microphone was enabled during the measurement. The FP35 may use a reference microphone for both coupler and real-ear measurements. The 7000 will only use a reference microphone for real-ear measurements.

Value | Description
0 | Reference microphone disabled
1 | Reference microphone enabled

## Smoothing status (Flag 0, Bit 5) [doesn’t indicate what type of smoothing?]

Bit 5 of flag 0 indicates whether the smoothing status of the measurement. The FP35 may use a smoothing for both coupler and real-ear measurements. The 7000 will only use smoothing for real-ear measurements.

Value | Description
0 | Smoothing disabled
1 | Smoothing enabled

## Filtering (Flag 0, Bits 8-9) [remove unless example of use is found, possibly indicate TRMS vs ERMS, etc]

Bits 8-9 of flag 0 indicate whether the source signal has been filtered (speech weighted), and whether the measurement data is accounting for that filter or giving raw measurement data (usually an indication of whether the measurement data is in gain or output).

Value | Description
0 | No filtering
2 | Source filtered, measurement data raw
3 | Source filtered, measurement data filtered

## Leveling status (Flag 0, Bit 13)

Bit 13 of flag 0 indicates whether the source is leveled. "Semi-leveled" is considered "leveled" in the curve frame.

Value | Description
0 | Not leveled
1 | Leveled

## Gain status (Flag 0 Bit 14)

Bit 14 of flag 0 indicates whether the measurement curve is Gain or SPL.

Value | Description
0 | SPL (output)
1 | Gain (output minus input)

## Curve Reference (Flag 0 Bit 15, Flag 1 Bit 5) [only used for REUR]use for REIG, target UCL too?

Bit 15 of flag 0 and bit 5 of flag 1 indicates if the curve is measured, computed, average, or predicted.

Value | Description
0 | Measured
1 | Computed/difference
2 | Average
3 | Predicted

## Modification Status (Flag 1 Bit 2)

Bit 2 of flag 1 indicates whether the curve has been modified after it was measured or calculated..

Value | Description
0 | Not modified
1 | Modified

## Curve Type Identifier (Flag 1, Bits 8-11) [Numbering can be unique for type 4, combine real-ear into single value]

Bits 8-12 of flag 1 contain the curve type identifier:

Value | Description
0 | Coupler curve vs freq
1 | Probe curve vs freq
2 | Distortion vs freq
3 | I / O vs input SPL
4 | Leveling curve vs freq
5 | Battery curve vs freq or input SPL
6 | Target curve vs freq
7 | Audiogram curve vs freq
8 | Polar curve vs angle
9 | dB or Linear vs time
10 |
11 |

## Curve Sub-type (Flag 1, Bit 12-15) [per curve type] [x-axis label always at #15?]

The curve sub-type values vary depending upon the curve frame format and the curve type identifier.

Curve type Coupler (0) has the following sub-types:

Value | Description
0 | Unknown
1 | Flat weighted
2 | ANSI weighting
3 | ICRA weighting
4 | UWO child LTASS
5 | Cox & Moore adult LTASS
7 | ANSI 92 weighting
8 | Telecoil(unleveled & unweighted)
9 | Frequency List

Curve type Probe (1) has the following sub-types:

Value | Description
0 | Unknown
1 | Flat weighted
2 | ANSI weighting
3 | ICRA weighting
4 | UWO child LTASS
5 | Cox & Moore adult LTASS
7 | ANSI 92 weighting
8 | Earphone (unleveled & unweighted)
9 | Frequency List

Curve type Distortion(2) has the following sub-types.

Value | Description
0 | No distortion measured
1 | 2nd harmonic distortion
2 | 3rd harmonic distortion
3 | Total harmonic distortion
4 | Frequency List

Curve type I/O(3) has the following sub-types.

Value | Description
0 | dB response
1 | Input SPL list

Curve type Leveling (4) has the following sub-types:

Value | Description
0 | Frequency List
1 | Leveling factor

Curve type Battery(5) has the following sub-types:

Value | Description
0 | Current draw vs freq
1 | Current draw vs level
2 | Freq list
3 | Input SPL list

Curve type Targets (6) has the following sub-types:

Value | Description
0 | NAL-R
1 | POGO
2 | Berger
3 | 1/3 Gain
4 | 1/2 Gain
5 | 2/3 Gain
6 | DSL linear
7 | DSL WDRC
8 | NAL-NL1
13 | Frequency List
14 | Other
15 | Direct

Curve types Audiogram (7) have the following sub-types:

Value | Description
0 | dB Response
1 | Frequency List

Curve type Polar (8) has the following sub-types:

Value | Description
0 | dB Response
1 | Angle List

Curve types Time domain (9) have the following sub-types:

Value | Description
0 | dB Response
1 | Linear Response
2 | Time List

Note: This includes R/A(dB), EDSP(linear), etc.

Original Flag Inventory:

Flag 0: Bit 0(Source type), Bits 1-2(Distortion type), Bit 3(Correction factors), Bit 4(Ref Mic), Bit 5(Smoothing), Bits 6-7(Transducer), Bits 8-9(Filtering),

Bits 10-12(Curve frame format), Bit 13(Leveling status), Bit 14(Gain status), Bit 15(Curve reference).

Flag 1: Bit 0(Correction factors), Bit 1(UNDEFINED), Bit 2(Modified), Bits 3-4(Source type), Bit 5(Curve reference), Bit 6(Source type), Bit 7(Correction factors),

Bits 8-11(Curve type ID), Bits 12-15(Curve subtype).

New Flag Inventory:

Flag 0: Bit 0(Source type), Bits 1-2(Available), Bit 3(Correction factors), Bit 4(Ref Mic), Bit 5(Smoothing), Bits 6-7(Available), Bits 8-9(Filtering),

Bits 10-12(Curve frame format), Bit 13(Leveling status), Bit 14(Gain status), Bit 15(Curve reference).

Flag 1: Bit 0(Correction factors), Bit 1(UNDEFINED), Bit 2(Modified), Bits 3-4(Source type), Bit 5(Curve reference), Bit 6(Source type), Bit 7(Correction factors),

Bits 8-11(Curve type ID), Bits 12-15(Curve subtype).

Notes from Aaron: Reallocate Flag 0 bits 1-2 for source filter?