MIL-STD-810G Method 515.6 acoustic noise test parameters. Two data types: (1) OASPL (Overall Sound Pressure Level, dB re 20 uPa) test levels and required test durations by application category including transport aircraft, high-performance aircraft, missiles, airborne rockets, and ground engine runup areas (Table 515.6A-I). (2) Normalized 1/3-octave spectral shape giving nominal level offsets and tolerance bands (dB relative to OASPL) at 24 center frequencies from 50 Hz to 10 kHz (Table 515.6A-III). The spectral shape is used to define the test spectrum once the OASPL level is set from the OASPL records.