Parameters Overview

The calculation parameters of most of the indicators available in Ansys Sound: Analysis and Specification can be configured from the Custom Profile settings. This section gives the details about these parameters.

Level vs. Time

Parameter

Description

Sound level meter setting

This parameter sets the calculation of the temporal levels. Three calculation modes are available, according to the IEC 61272-1 standard:

  • Slow,

  • Fast,

  • Impulse

    Note: According to the IEC 61272-1 standard, the temporal level at time t is:
    where:
    • is the X-weighted power at time
    • is the reference pressure
    • is the time associated with the setting: 35ms for Impulse, 125ms for Fast, 1000ms for Slow.

If you want set the temporal levels manually, select Customized, then set the Time step, Window size and the type of Analysis window.

Time step (ms)

This parameter is associated to the above mentioned Customized parameter. It corresponds to the step between two level calculations.

Window size (ms)

This parameter is associated to the above-mentioned Customized parameter. It corresponds to the size of the analysis window.

Note: The longer the window is, the smoother the curve is.

Analysis window

This parameter is associated to the above-mentioned Customized parameter. It corresponds to the type of analysis window:

  • Rectangular,

  • Hann,

  • Hamming,

  • Blackman,

  • Blackman-Harris,

  • Bartlett.

ISO1996-2 Tonality

Parameter

Description

Non-stationary mode

This mode performs the calculation at different time steps of the signal defined by the following parameters:

  • Integration window length which refers to the size of the window in millisecond for each calculation step.

  • Overlap (%) which defines the overlap between each consecutive time window.

    The Non-stationary mode is not included in the ISO1996 standard.

Noise pause Detection threshold

This parameters is a positive value in dB.

Effective analysis bandwidth

This parameter refers to the effective frequency resolution of the calculated spectra.

Important: Value has to be lower than 5 Hz.

Noise bandwidth

This parameter refers to the bandwidth taken into account for estimating the noise level.

Important: The value has to range between 0.75 and 2 (+/- CB - Critical Bandwidth).

DIN45681 Tonality

Parameter

Description

Integration window length

This parameter sets the integration window length in millisecond.

Overlap

This parameter allows you to set the overlap percentage applied to the window length.

Aures Tonality

Parameter

Description

Overlap

This parameter allows you to set the overlap percentage applied to the window length.

Bandwidth weighting w1

When enabled, this option includes this weighting in the calculation.

For further details, see Aures Tonality

Polynomial Comfort Equation Settings

Adjust the coefficient and exponent values for:

Intelligibility

Parameter

Description

Integration window length (ms)

This parameter sets the integration window length in millisecond.