Tonal Noise
Noise with distinct tones, for example, noise from fans, compressors, or saws, is generally far more annoying than other types of noise. This annoyance factor is not taken into account in a broadband measurement. A spectral analysis may be needed to assess annoyance.
我查到的,还是想不出这个噪声到底该叫啥
What Is Tonal Noise?
Tonal noise is commonly referred to as discrete frequency noise and is characterized by spectral tones that are pure tone in nature. Pure tones are wave forms that occur at a single frequency. Tonal noise is generated by rotating equipment at a predictable frequency relating to the rotational speed of the shaft and the number of compressor vanes, fan blades, engine pistons, gear teeth, etc. The fundamental tone (F) may also manifest itself at progressively lower intensity levels at integer harmonic multiples (2F, 3F, etc.). Tolerance levels for tonal noise are generally at a lower threshold.