What is octave frequency?
The octave and the 1/3 octave band frequencies. The audible frequency range can be separated into unequal segments called octaves. An octave higher is a doubling of the octave band frequency. Octave bands can be separated into three ranges - referred to as one-third-octave bands. listen to the sound! - touch and click the frequency below!
What is the bandwidth of a one-third octave band?
For a one-third octave band with centre frequency f, the bandwidth is 0.23 f. To ensure three narrow-band spectral lines within the band, 3/ T ? 0.23 f or f ? 13/ T. For an analysis length L of 1.2 m this is (almost) satisfied at a wavelength of 100 mm (1/12 of the analysis length).
How are octave levels calculated?
octave levels first, but directly determines frequency group levels with a width of 1/5 Bark. The calculation is FFT-based and takes both the upper and the lower accessory loudness into account. Afterwards, the levels are corrected based on the transfer characteristics of the ear for a free field or a diffuse field.
What is one-third octave roughness data?
One-third octave roughness data is normally used to produce corresponding noise predictions and should therefore ideally be provided at wavelengths corresponding to the standard frequencies. This means that the wavelengths required depend on the train speed.