Descriptors

The descriptors module offers all kinds of acoustics related descriptors.

Descriptors from ISO/TR 25417:2007

Descriptors from acoustics.standards.iso_tr_25417_2007.

descriptors.REFERENCE_PRESSURE = 2e-05
acoustics.descriptors.sound_pressure_level(pressure, reference_pressure=2e-05)[source]

Sound pressure level \(L_p\) in dB.

Parameters:
  • pressure – Instantaneous sound pressure \(p\).
  • reference_pressure – Reference value \(p_0\).
\[L_p = 10 \log_{10}{ \left( \frac{p^2}{p_0^2} \right)}\]

See section 2.2.

acoustics.descriptors.equivalent_sound_pressure_level(pressure, reference_pressure=2e-05, axis=-1)[source]

Time-averaged sound pressure level \(L_{p,T}\) or equivalent-continious sound pressure level \(L_{p,eqT}\) in dB.

Parameters:
  • pressure – Instantaneous sound pressure \(p\).
  • reference_pressure – Reference value \(p_0\).
  • axis – Axis.
\[L_{p,T} = L_{p,eqT} = 10.0 \log_{10}{ \left( \frac{\frac{1}{T} \int_{t_1}^{t_2} p^2 (t) \mathrm{d} t }{p_0^2} \right)}\]

See section 2.3.

acoustics.descriptors.peak_sound_pressure(pressure, axis=-1)[source]

Peak sound pressure \(p_{peak}\) is the greatest absolute sound pressure during a certain time interval.

Parameters:
  • pressure – Instantaneous sound pressure \(p\).
  • axis – Axis.
\[p_{peak} = \mathrm{max}(|p|)\]
acoustics.descriptors.peak_sound_pressure_level(pressure, reference_pressure=2e-05, axis=-1)[source]

Peak sound pressure level \(L_{p,peak}\) in dB.

Parameters:
  • pressure – Instantaneous sound pressure \(p\).
  • reference_pressure – Reference value \(p_0\).
  • axis – Axis.
\[L_{p,peak} = 10.0 \log \frac{p_{peak}^2.0}{p_0^2}\]
descriptors.REFERENCE_SOUND_EXPOSURE = 4e-10
acoustics.descriptors.sound_exposure(pressure, fs, axis=-1)[source]

Sound exposure \(E_{T}\).

Parameters:
  • pressure – Instantaneous sound pressure \(p\).
  • fs – Sample frequency \(f_s\).
  • axis – Axis.
\[E_T = \int_{t_1}^{t_2} p^2 (t) \mathrm{d}t\]
acoustics.descriptors.sound_exposure_level(pressure, fs, reference_sound_exposure=4e-10, axis=-1)[source]

Sound exposure level \(L_{E,T}\) in dB.

Parameters:
  • pressure – Instantaneous sound pressure \(p\).
  • fs – Sample frequency \(f_s\).
  • sound_exposure – Sound exposure \(E_{T}\).
  • reference_sound_exposure – Reference value \(E_{0}\)
\[L_{E,T} = 10 \log_{10}{ \frac{E_T}{E_0} }\]
descriptors.REFERENCE_POWER = 1e-12
acoustics.descriptors.sound_power_level(power, reference_power=1e-12)[source]

Sound power level \(L_{W}\).

Parameters:
  • power – Sound power \(P\).
  • reference_power – Reference sound power \(P_0\).
\[10 \log_{10}{ \frac{P}{P_0} }\]
acoustics.descriptors.sound_energy(power, axis=-1)[source]

Sound energy \(J\)..

Parameters:power – Sound power \(P\).
\[J = \int_{t_1}^{t_2} P(t) \mathrm{d} t\]
acoustics.descriptors.sound_energy_level(energy, reference_energy=1e-12)[source]

Sound energy level L_{J} in dB.

Parameters:
  • energy – Sound energy \(J\).
  • reference_energy – Reference sound energy \(J_0\).
\[L_{J} = 10 \log_{10}{ \frac{J}{J_0} }\]
descriptors.REFERENCE_ENERGY = 1e-12
acoustics.descriptors.sound_intensity(pressure, velocity)[source]

Sound intensity \(\mathbf{i}\).

Parameters:
  • pressure – Sound pressure \(p(t)\).
  • velocity – Particle velocity \(\mathbf{u}(t)\).
\[\mathbf{i} = p(t) \cdot \mathbf{u}(t)\]
acoustics.descriptors.time_averaged_sound_intensity(intensity, axis=-1)[source]

Time-averaged sound intensity \(\mathbf{I}_T\).

Parameters:
  • intensity – Sound intensity \(\mathbf{i}\).
  • axis – Axis.
\[\mathbf{I}_T = \frac{1}{T} \int_{t_1}^{t_2} \mathbf{i}(t)\]
descriptors.REFERENCE_INTENSITY = 1e-12
acoustics.descriptors.time_averaged_sound_intensity_level(time_averaged_sound_intensity, reference_intensity=1e-12, axis=-1)[source]

Time-averaged sound intensity level \(L_{I,T}\).

Parameters:
  • time_averaged_sound_intensity – Time-averaged sound intensity \(\mathbf{I}_T\).
  • reference_intensity – Reference sound intensity \(I_0\).
\[L_{I,T} = 10 \log_{10} { \frac{|\mathbf{I}_T|}{I_0} }\]
acoustics.descriptors.normal_time_averaged_sound_intensity(time_averaged_sound_intensity, unit_normal_vector)[source]

Normal time-averaged sound intensity \(I_{n,T}\).

Parameters:
  • time_averaged_sound_intensity – Time-averaged sound intensity \(\mathbf{I}_T\).
  • unit_normal_vector – Unit normal vector \(\mathbf{n}\).
\[I_{n,T} = \mathbf{I}_T \cdot \mathbf{n}\]
acoustics.descriptors.normal_time_averaged_sound_intensity_level(normal_time_averaged_sound_intensity, reference_intensity=1e-12)[source]

Normal time-averaged sound intensity level \(L_{In,T}\) in dB.

Parameters:
  • normal_time_averaged_sound_intensity – Normal time-averaged sound intensity \(I{n,T}\).
  • reference_intensity – Reference sound intensity \(I_0\).
\[I_{n,T} = 10 \log_{10} { \frac{|I_{n,T}|}{I_0}}\]

Other descriptors

acoustics.descriptors.sound_pressure_level(pressure, reference_pressure=2e-05)[source]

Sound pressure level \(L_p\) in dB.

Parameters:
  • pressure – Instantaneous sound pressure \(p\).
  • reference_pressure – Reference value \(p_0\).
\[L_p = 10 \log_{10}{ \left( \frac{p^2}{p_0^2} \right)}\]

See section 2.2.

acoustics.descriptors.equivalent_sound_pressure_level(pressure, reference_pressure=2e-05, axis=-1)[source]

Time-averaged sound pressure level \(L_{p,T}\) or equivalent-continious sound pressure level \(L_{p,eqT}\) in dB.

Parameters:
  • pressure – Instantaneous sound pressure \(p\).
  • reference_pressure – Reference value \(p_0\).
  • axis – Axis.
\[L_{p,T} = L_{p,eqT} = 10.0 \log_{10}{ \left( \frac{\frac{1}{T} \int_{t_1}^{t_2} p^2 (t) \mathrm{d} t }{p_0^2} \right)}\]

See section 2.3.

acoustics.descriptors.peak_sound_pressure(pressure, axis=-1)[source]

Peak sound pressure \(p_{peak}\) is the greatest absolute sound pressure during a certain time interval.

Parameters:
  • pressure – Instantaneous sound pressure \(p\).
  • axis – Axis.
\[p_{peak} = \mathrm{max}(|p|)\]
acoustics.descriptors.peak_sound_pressure_level(pressure, reference_pressure=2e-05, axis=-1)[source]

Peak sound pressure level \(L_{p,peak}\) in dB.

Parameters:
  • pressure – Instantaneous sound pressure \(p\).
  • reference_pressure – Reference value \(p_0\).
  • axis – Axis.
\[L_{p,peak} = 10.0 \log \frac{p_{peak}^2.0}{p_0^2}\]
acoustics.descriptors.sound_exposure(pressure, fs, axis=-1)[source]

Sound exposure \(E_{T}\).

Parameters:
  • pressure – Instantaneous sound pressure \(p\).
  • fs – Sample frequency \(f_s\).
  • axis – Axis.
\[E_T = \int_{t_1}^{t_2} p^2 (t) \mathrm{d}t\]
acoustics.descriptors.sound_exposure_level(pressure, fs, reference_sound_exposure=4e-10, axis=-1)[source]

Sound exposure level \(L_{E,T}\) in dB.

Parameters:
  • pressure – Instantaneous sound pressure \(p\).
  • fs – Sample frequency \(f_s\).
  • sound_exposure – Sound exposure \(E_{T}\).
  • reference_sound_exposure – Reference value \(E_{0}\)
\[L_{E,T} = 10 \log_{10}{ \frac{E_T}{E_0} }\]
acoustics.descriptors.sound_power_level(power, reference_power=1e-12)[source]

Sound power level \(L_{W}\).

Parameters:
  • power – Sound power \(P\).
  • reference_power – Reference sound power \(P_0\).
\[10 \log_{10}{ \frac{P}{P_0} }\]
acoustics.descriptors.sound_energy(power, axis=-1)[source]

Sound energy \(J\)..

Parameters:power – Sound power \(P\).
\[J = \int_{t_1}^{t_2} P(t) \mathrm{d} t\]
acoustics.descriptors.sound_energy_level(energy, reference_energy=1e-12)[source]

Sound energy level L_{J} in dB.

Parameters:
  • energy – Sound energy \(J\).
  • reference_energy – Reference sound energy \(J_0\).
\[L_{J} = 10 \log_{10}{ \frac{J}{J_0} }\]
acoustics.descriptors.sound_intensity(pressure, velocity)[source]

Sound intensity \(\mathbf{i}\).

Parameters:
  • pressure – Sound pressure \(p(t)\).
  • velocity – Particle velocity \(\mathbf{u}(t)\).
\[\mathbf{i} = p(t) \cdot \mathbf{u}(t)\]
acoustics.descriptors.time_averaged_sound_intensity(intensity, axis=-1)[source]

Time-averaged sound intensity \(\mathbf{I}_T\).

Parameters:
  • intensity – Sound intensity \(\mathbf{i}\).
  • axis – Axis.
\[\mathbf{I}_T = \frac{1}{T} \int_{t_1}^{t_2} \mathbf{i}(t)\]
acoustics.descriptors.time_averaged_sound_intensity_level(time_averaged_sound_intensity, reference_intensity=1e-12, axis=-1)[source]

Time-averaged sound intensity level \(L_{I,T}\).

Parameters:
  • time_averaged_sound_intensity – Time-averaged sound intensity \(\mathbf{I}_T\).
  • reference_intensity – Reference sound intensity \(I_0\).
\[L_{I,T} = 10 \log_{10} { \frac{|\mathbf{I}_T|}{I_0} }\]
acoustics.descriptors.normal_time_averaged_sound_intensity(time_averaged_sound_intensity, unit_normal_vector)[source]

Normal time-averaged sound intensity \(I_{n,T}\).

Parameters:
  • time_averaged_sound_intensity – Time-averaged sound intensity \(\mathbf{I}_T\).
  • unit_normal_vector – Unit normal vector \(\mathbf{n}\).
\[I_{n,T} = \mathbf{I}_T \cdot \mathbf{n}\]
acoustics.descriptors.normal_time_averaged_sound_intensity_level(normal_time_averaged_sound_intensity, reference_intensity=1e-12)[source]

Normal time-averaged sound intensity level \(L_{In,T}\) in dB.

Parameters:
  • normal_time_averaged_sound_intensity – Normal time-averaged sound intensity \(I{n,T}\).
  • reference_intensity – Reference sound intensity \(I_0\).
\[I_{n,T} = 10 \log_{10} { \frac{|I_{n,T}|}{I_0}}\]
acoustics.descriptors.leq(levels, int_time=1.0)[source]

Equivalent level \(L_{eq}\).

Parameters:
  • levels – Levels as function of time.
  • int_time – Integration time. Default value is 1.0 second.
Returns:

Equivalent level L_{eq}.

Sum of levels in dB.

acoustics.descriptors.sel(levels)[source]

Sound Exposure Level from levels (NumPy array).

acoustics.descriptors.lw(W, Wref=1e-12)[source]

Sound power level \(L_{w}\) for sound power \(W\) and reference power \(W_{ref}\).

Parameters:
  • W – Sound power \(W\).
  • Wref – Reference power \(W_{ref}\). Default value is \(10^{12}\) watt.
acoustics.descriptors.lden(lday, levening, lnight, hours=(12.0, 4.0, 8.0), adjustment=(0.0, 5.0, 10.0))[source]

Calculate \(L_{den}\) from \(L_{day}\), \(L_{evening}\) and \(L_{night}\).

Parameters:
  • lday – Equivalent level during day period \(L_{day}\).
  • levening – Equivalent level during evening period \(L_{evening}\).
  • lnight – Equivalent level during night period \(L_{night}\).
  • hours – Hours per period.
  • adjustment – Correction factor per period.
Returns:

\(L_{den}\)

See also

acoustics.standards.iso_1996_1_2003.composite_rating_level()

acoustics.descriptors.ldn(lday, lnight, hours=(15.0, 9.0), adjustment=(0.0, 10.0))[source]

Calculate \(L_{dn}\) from \(L_{day}\) and \(L_{night}\).

Parameters:
  • lday – Equivalent level during day period \(L_{day}\).
  • lnight – Equivalent level during night period \(L_{night}\).
  • hours – Hours per period.
  • adjustment – Correction factor per period.
Returns:

\(L_{dn}\)

See also

acoustics.standards.iso_1996_1_2003.composite_rating_level()