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Weighting Module

Weightings according to IEC 61672-1:2003.

ATTRIBUTE DESCRIPTION
THIRD_OCTAVE_A_WEIGHTING

A-weighting filter for preferred ⅓-octave band center frequencies.
THIRD_OCTAVE_C_WEIGHTING

C-weighting filter for preferred ⅓-octave band center frequencies.
FUNCTION DESCRIPTION
a_weighting

A-weighting.
c_weighting

C-weighting.
z2a

Apply A-weighting to Z-weighted signal.
a2z

Remove A-weighting from A-weighted signal.
z2c

Apply C-weighting to Z-weighted signal.
c2z

Remove C-weighting from C-weighted signal.

Attributes

THIRD_OCTAVE_A_WEIGHTING module-attribute 

THIRD_OCTAVE_A_WEIGHTING = array(
    [
        -63.4,
        -56.7,
        -50.5,
        -44.7,
        -39.4,
        -34.6,
        -30.2,
        -26.2,
        -22.5,
        -19.1,
        -16.1,
        -13.4,
        -10.9,
        -8.6,
        -6.6,
        -4.8,
        -3.2,
        -1.9,
        -0.8,
        +0.0,
        +0.6,
        +1.0,
        +1.2,
        +1.3,
        +1.2,
        +1.0,
        +0.5,
        -0.1,
        -1.1,
        -2.5,
        -4.3,
        -6.6,
        -9.3,
    ]
)

A-weighting filter for preferred ⅓-octave band center frequencies, as specified in acoustic_toolbox.bands.THIRD_OCTAVE_CENTER_FREQUENCIES.

THIRD_OCTAVE_C_WEIGHTING module-attribute 

THIRD_OCTAVE_C_WEIGHTING = array(
    [
        -11.2,
        -8.5,
        -6.2,
        -4.4,
        -3.0,
        -2.0,
        -1.3,
        -0.8,
        -0.5,
        -0.3,
        -0.2,
        -0.1,
        +0.0,
        +0.0,
        +0.0,
        +0.0,
        +0.0,
        +0.0,
        +0.0,
        +0.0,
        +0.0,
        -0.1,
        -0.2,
        -0.3,
        -0.5,
        -0.8,
        -1.3,
        -2.0,
        -3.0,
        -4.4,
        -6.2,
        -8.5,
        -11.2,
    ]
)

C-weighting filter for preferred ⅓-octave band center frequencies, as specified in acoustic_toolbox.bands.THIRD_OCTAVE_CENTER_FREQUENCIES.

Functions

a_weighting 

a_weighting(first: float, last: float) -> ndarray

Select frequency weightings between first and last centerfrequencies from A-weighting.

Possible values for these frequencies are third-octave frequencies between 12.5 Hz and 20,000 Hz (including them).

PARAMETER DESCRIPTION
first

First third-octave centerfrequency.

TYPE: float

last

Last third-octave centerfrequency.

TYPE: float

RETURNS DESCRIPTION
ndarray

A-weighting between first and last center frequencies.
Source code in acoustic_toolbox/weighting.py 
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def a_weighting(first: float, last: float) -> np.ndarray:
    """Select frequency weightings between ``first`` and ``last`` centerfrequencies from A-weighting.

    Possible values for these frequencies are third-octave frequencies
    between 12.5 Hz and 20,000 Hz (including them).

    Args:
      first: First third-octave centerfrequency.
      last: Last third-octave centerfrequency.

    Returns:
        A-weighting between `first` and `last` center frequencies.
    """
    return _weighting("a", first, last)

c_weighting 

c_weighting(first: float, last: float) -> ndarray

Select frequency weightings between first and last centerfrequencies from C-weighting.

Possible values for these frequencies are third-octave frequencies between 12.5 Hz and 20,000 Hz (including them).

PARAMETER DESCRIPTION
first

First third-octave centerfrequency.

TYPE: float

last

Last third-octave centerfrequency.

TYPE: float

RETURNS DESCRIPTION
ndarray

C-weighting between first and last center frequencies.
Source code in acoustic_toolbox/weighting.py 
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def c_weighting(first: float, last: float) -> np.ndarray:
    """Select frequency weightings between ``first`` and ``last`` centerfrequencies from C-weighting.

    Possible values for these frequencies are third-octave frequencies
    between 12.5 Hz and 20,000 Hz (including them).

    Args:
      first: First third-octave centerfrequency.
      last: Last third-octave centerfrequency.

    Returns:
        C-weighting between `first` and `last` center frequencies.
    """
    return _weighting("c", first, last)

z2a 

z2a(levels: ndarray, first: float, last: float) -> ndarray

Apply A-weighting to Z-weighted signal.

PARAMETER DESCRIPTION
levels

Z-weighted signal.

TYPE: ndarray

first

First third-octave centerfrequency.

TYPE: float

last

Last third-octave centerfrequency.

TYPE: float

RETURNS DESCRIPTION
ndarray

A-weighted signal.
Source code in acoustic_toolbox/weighting.py 
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def z2a(levels: np.ndarray, first: float, last: float) -> np.ndarray:
    """Apply A-weighting to Z-weighted signal.

    Args:
      levels: Z-weighted signal.
      first: First third-octave centerfrequency.
      last: Last third-octave centerfrequency.

    Returns:
        A-weighted signal.
    """
    return levels + a_weighting(first, last)

a2z 

a2z(levels: ndarray, first: float, last: float) -> ndarray

Remove A-weighting from A-weighted signal.

PARAMETER DESCRIPTION
levels

A-weighted signal.

TYPE: ndarray

first

First third-octave centerfrequency.

TYPE: float

last

Last third-octave centerfrequency.

TYPE: float

RETURNS DESCRIPTION
ndarray

Z-weighted signal.
Source code in acoustic_toolbox/weighting.py 
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def a2z(levels: np.ndarray, first: float, last: float) -> np.ndarray:
    """Remove A-weighting from A-weighted signal.

    Args:
      levels: A-weighted signal.
      first: First third-octave centerfrequency.
      last: Last third-octave centerfrequency.

    Returns:
        Z-weighted signal.
    """
    return levels - a_weighting(first, last)

z2c 

z2c(levels: ndarray, first: float, last: float) -> ndarray

Apply C-weighting to Z-weighted signal.

PARAMETER DESCRIPTION
levels

Z-weighted signal.

TYPE: ndarray

first

First third-octave centerfrequency.

TYPE: float

last

Last third-octave centerfrequency.

TYPE: float

RETURNS DESCRIPTION
ndarray

C-weighted signal.
Source code in acoustic_toolbox/weighting.py 
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def z2c(levels: np.ndarray, first: float, last: float) -> np.ndarray:
    """Apply C-weighting to Z-weighted signal.

    Args:
      levels: Z-weighted signal.
      first: First third-octave centerfrequency.
      last: Last third-octave centerfrequency.

    Returns:
        C-weighted signal.
    """
    return levels + c_weighting(first, last)

c2z 

c2z(levels: ndarray, first: float, last: float) -> ndarray

Remove C-weighting from C-weighted signal.

PARAMETER DESCRIPTION
levels

C-weighted signal.

TYPE: ndarray

first

First third-octave centerfrequency.

TYPE: float

last

Last third-octave centerfrequency.

TYPE: float

RETURNS DESCRIPTION
ndarray

Z-weighted signal.
Source code in acoustic_toolbox/weighting.py 
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def c2z(levels: np.ndarray, first: float, last: float) -> np.ndarray:
    """Remove C-weighting from C-weighted signal.

    Args:
      levels: C-weighted signal.
      first: First third-octave centerfrequency.
      last: Last third-octave centerfrequency.

    Returns:
        Z-weighted signal.
    """
    return levels - c_weighting(first, last)

a2c 

a2c(levels: ndarray, first: float, last: float) -> ndarray

Go from A-weighted to C-weighted.

PARAMETER DESCRIPTION
levels

A-weighted signal.

TYPE: ndarray

first

First third-octave centerfrequency.

TYPE: float

last

Last third-octave centerfrequency.

TYPE: float

RETURNS DESCRIPTION
ndarray

C-weighted signal.
Source code in acoustic_toolbox/weighting.py 
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def a2c(levels: np.ndarray, first: float, last: float) -> np.ndarray:
    """Go from A-weighted to C-weighted.

    Args:
      levels: A-weighted signal.
      first: First third-octave centerfrequency.
      last: Last third-octave centerfrequency.

    Returns:
        C-weighted signal.
    """
    dB = a2z(levels, first, last)
    return z2c(dB, first, last)

c2a 

c2a(levels: ndarray, first: float, last: float) -> ndarray

Go from C-weighted to A-weighted.

PARAMETER DESCRIPTION
levels

C-weighted signal.

TYPE: ndarray

first

First third-octave centerfrequency.

TYPE: float

last

Last third-octave centerfrequency.

TYPE: float

RETURNS DESCRIPTION
ndarray

A-weighted signal.
Source code in acoustic_toolbox/weighting.py 
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def c2a(levels: np.ndarray, first: float, last: float) -> np.ndarray:
    """Go from C-weighted to A-weighted.

    Args:
      levels: C-weighted signal.
      first: First third-octave centerfrequency.
      last: Last third-octave centerfrequency.

    Returns:
        A-weighted signal.
    """
    dB = c2z(levels, first, last)
    return z2a(dB, first, last)

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