Sound Exposure Level (MHKiT-Software#388)

add sound exposure level (SEL) and SEL weighting

Author: jmcvey3

examples/acoustics_example.ipynb

@@ -16,4 +16,17 @@
 """
 
 from mhkit.acoustics import io, graphics
-from .analysis import *
+from .analysis import (
+    minimum_frequency,
+    sound_pressure_spectral_density,
+    apply_calibration,
+    sound_pressure_spectral_density_level,
+    band_aggregate,
+    time_aggregate,
+)
+from .spl import (
+    sound_pressure_level,
+    third_octave_sound_pressure_level,
+    decidecade_sound_pressure_level,
+)
+from .sel import nmfs_auditory_weighting, sound_exposure_level