Octave Band Noise

The octave band noise is a noise signal that extracts only energy of a bandwidth of a certain one octave frequency with respect to white noise and pink noise. Our app "Octave Band Noise Generator" provides an octave band noise or 1/3 octave band noise can be output programmably.

I will explain the octave band noise in more detail. An octave is a pitch that doubles the ratio of frequencies to a certain frequency. And the octave band is the bandwidth of the frequency where the ratio of the upper and lower frequencies centered on a certain frequency is exactly one octave. The center frequency of this octave band is called the center frequency, and the frequency band for the center frequency fo ranges from the lower limit frequency fo/√ 2 to the upper limit frequency fo*√2. For example, the center frequency of an octave band is 1 kHz, 2 kHz, 4 kHz ,,,, and one octave is divided into three in the 1/3 octave band.

The octave band noise is a noise signal that extracts only a specific octave band (specific frequency band) with the band-pass filter with the octave band characteristics as above.
Using this octave band noise, it is possible to evaluate only the target frequency band. By measuring the pink noise of a specific frequency band with a real-time analyzer, it is possible to make sound adjustments and measure noise source characteristics that are not affected by other frequency bands.

The generated noise signal by "Octave Band Noise Generator" can be used for various purposes as a reference sound source for environmental sound measurement, sound tuning, auditory effects like tinnitus relief and sound masking.

The followings are examples as a sound source for a room acoustic and environmental sound measurement.
- Sound source for the sound insulation level measurement.
- Sound source for the indoor sound field distribution measurement.
- Sound source for the reverberation time measurement.


As other applications, Octave band noise is also useful to adjust the characteristics of the audibility of earphones or headphones. For instance, by selecting the pink noise and playing the 1/1 octave band noise in the order of 125Hz, 1KHz, 8kHz of the center frequency, you can determine the intensity of each frequency band on the audibility. For more detail analyzing, please try in other octave bands or 1/3 octave noise. If you know the characteristic of frequency band, you will be able to adjust the earphone in the equalizer to your favorite sound easily.

posted by toons at 23:42 | Sound