2017年02月23日

Pink noise

Pink noise is a noise sound that the power is inversely proportional to frequency, and the energy per octave is constant. It is a noise passed through a low pass filter of -3dB/ oct for White noise. On the other hand, White noise is such that the energy of each frequency is constant, and the energy level rises at the rate of +3dB/oct when the frequency increases.

Therefore, Pink noise becomes a frequency characteristic that goes down to the right as the frequency increases. Since the energy for each constant frequency band becomes uniform, it is noise suitable for the purpose of evaluating the volume of each frequency band. Pink noise is often used for sound adjustment and measurement because the sound intensity is the same in any octave band.

Incidentally, it is said that Pink noise is the same as what is said to be "1/f fluctuation" or "1/f noise" and it is said to be close to the distribution of sound in the natural world. Since Pink noise resembles an actual music signal because it has a spectrum, you can give the sound system the same stress as the music signal.

For example, you can measure the frequency characteristics of a sound system and calibrate it using an octave band or 1/3 octave band real-time analyzer.
At this time, our Realtime Analyzer application "Audio Frequency Analyzer" and "fo-Kannon" are also available. If you play back Pink noise from your audio system, it measures the characteristic frequency spectrum by setting of LEVEL and HOLD in the 1/3 Octave mode on our app. You can see the overall frequency response result of the audio playback environment. While feedback in realtime by using this result, you can easily improve the sound quality of your audio environment.

posted by toon-rd-team at 17:39| Sound

2017年02月21日

White noise

White noise is a wave that vibrates irregularly and usually refers to noise in the audible band.

White noise has the same amplitude at every frequency. When seeing with acoustic power in a frequency band of a fixed width, the power of frequency becomes 3 dB/oct higher as the frequency becomes higher. Also, Pink noise is a filter that attenuates White noise by 3 dB/oct per frequency. In addition, the name of "white" is because light containing all frequencies is white color.

White noise is often used in technical fields such as sound adjustment and acoustic measurement, but it is also applied in various fields in medical fields and social fields. For example, by listening to white noise, symptoms of people suffering from tinnitus are alleviated, listening to noise such as masking sounds makes it easier for people with insomnia to fall asleep, concentration of works, it has been reported that there are better effects.

In the sound-related, the broadband noise signal (White noise and Pink noise) is commonly used. In order to perform more detailed measurement evaluation and tuning, it is also used the testing signal that has the specific subdivided frequency bands like a 1/1 or 1/3 octave band noise.

We have four types of applications that can generate White noise and Pink noise. 
- "Audio Tone Generator" : This app can generate generic audio reference signal.
- "Audio Tone Generator Lite" : Simplified "Audio Tone Generator", it is a free app. It has an advertisement display.
- "Audio Tone Generator for iPad" : This app can generate generic audio reference signal ustomized for iPad.
- "Octave Band Noise Generator/Lite" : By using white noise and pink noise as the source signal, it can generate a specific noise signal divided in frequency band by 1/1 or 1/3 octave band. Any frequency band can be programmably selected and output.

posted by toon-rd-team at 21:11| Sound