# Response 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
0 | Pure-tone response with distortion | 64 plus 16
1 | Standard composite | 80
2 | Audiometric | 16

The information for curve frame formats 0 and 1 are very similar and are explained in this topic.

See Audiogram Curve Flags for information on the flags of curve frame format 2 (audiometric).

## 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

## Distortion Type (Flag 0, Bits 1-2)

The first two bits of data of flag 0 contain the distortion type of the curve. Harmonic distortion is only measured with a pure-tone source type.

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

## Correction Factors (Flag 1 Bit 7, Flag 1 Bit 0, Flag 0 Bit 3)

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)

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

## Transducer (Flag 0, Bits 6-7)

Bits 6-7 of flag 0 indicate whether the transducer used during the measurement.

Value | Description
0 | Sound chamber
1 | Telecoil
2 | Sound field speaker
3 | Earphone

## Filtering (Flag 0, Bits 8-9)

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)

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)

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

Value | Description
0 | Response curve
1 | Real-ear unaided gain (REUG)
2 | Real-ear aided gain (REAG)
4 | Real-ear aided gain (REIG)
5 | Leveling curve
7 | Battery curve
8 | Target curve
9 | Audiogram curve

## Curve Sub-type (Flag 1, Bit 12-15)

The curve sub-type values vary depending upon the curve frame format and the curve type identifier. Curve types Response (0), REUG (1), REAG (2), REIG (4) have 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

Curve types Targets (8) have 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
14 | Other
15 | Direct