由具有重要振动部件的能源驱动的旋转系统（如单相感应电动机）中的噪声和振动问题，有时是由旋转部件（如风扇、鼓风机或启动开关机构）对源振动力和/或扭矩的共振响应引起的。这些问题通常出现在单相感应电动机应用中，其中，令人不快的噪声或振动是由转矩脉动和/或轴向力单独或组合引起的，其特征是以偶数倍的线频率出现。 第三种径向模式下的振动响应可能是由多个可能频率下的不平衡径向（“两极”）磁力引起的。径向磁力的大小、磁极结构和频率主要取决于线频率；转子打滑；极对、转子槽和定子槽的数量；以及旋转和静止气隙不对称，这是制造过程特有的生产公差的正常结果。可追溯到单相感应电动机应用中固有电磁力的噪声包括从空气表面辐射的纯音- 安装在输出轴上的操作装置，其在足够大的表面积上表现出强迫振动（通常共振放大），足以辐射足够的声能，从而在装置附近产生令人不快的噪声级。已知（参考文献2）纯音比具有宽带（分布式）频谱的同一级别的噪声更烦人，例如典型的由移动空气产生的“白色”噪声。在感应电机应用中，纯音干扰有时会进一步增加，因为纯音之间的“拍”会导致发射噪声水平的低频变化，而纯音之间的频率差很小，这归因于转子打滑。 纯音噪声问题在住宅或办公室等低噪声环境中使用的空气处理设备或系统中并不少见。客户对此类应用的投诉，包括风扇和风扇。当纯音成分超出宽带背景水平达不到令人讨厌的程度时，加热或空调系统就可能出现故障。“令人反感”的定义有很大的差异，取决于纯音超过频谱附近部分噪声能量的其他成分的量、频率、应用、期望、个性和相互影响- 参与诊断和定义问题的个人之间的关系。客户、销售和技术人员以及电机制造商和空气移动设备制造商的管理层之间的互动难以量化，且高度可变，对于确定给定应用中发出的噪声是否会被定义为“问题”至关重要引文:伊利诺伊州芝加哥ASHRAE Transactions第83卷第1部分

Noise and vibration problems in rotating systems powered by energy sources with a significant vibrational component-- such as the single-phase induction motor -- are sometimes caused by resonant response of rotating parts, e.g., fans, blowers, or start switch mechanisms, to the source's vibratory forces and/or torques. These problems commonly occur in single-phase induction motor applications, in which objectionable noise or vibration is caused by the torque pulsations and/or axial forces, singly or in combination, which characteristically occur at even multiples of line frequency. Vibrational response in a third, radial, mode may result from unbalanced radial ("two-pole") magnetic forces at any of a multiplicity of possible frequencies. The magnitude, pole structure, and frequency of radial magnetic forces depend primarily upon line frequency; rotor slip; numbers of pole pairs, rotor slots, and stator slots; and rotating and stationary air-gap dissymmetries which are the normal result of production tolerances endemic to the manufacturing process.Noise traceable to the electromagnetic forces inherent in single-phase induction motor applications includes pure tones radiated from the surfaces of air-handling devices attached to the output shaft, which exhibit forced vibration (usually resonantly amplified) over surface areas large enough to radiate sufficient acoustical energy to produce objectionable noise levels in the vicinity of the device.Pure tones are known (Ref 2) to be more annoying than noise of the same levelwhich has a broadband (distributed) spectrum such as the "white" noise characteristically produced by moving air. Pure-tone annoyance is sometimes further increased in induction motor applications by the presence of the low-frequency variation in emitted noise level caused by "beats" between pure tones which have a small frequency difference attributed to rotor slip.Pure-tone noise problems occur not infrequently in air-handling devices or systems used in low-noise environments such as residences or offices. Customer complaints about such applications, including fan and. heating or air-conditioning systems, are likely whenever pure-tone components exceed the broadband background levels by an objectionable amount. The definition of "objectionable" is quite variable and depends on the amount by which the pure tones exceed the other components of noise energy in nearby parts of the spectrum, the frequencies, the application, and the expectations, personalities, and inter-relationships of the individuals involved in diagnosing and defining the problem. The interaction among the customers, the sales and technical staffs, and management of both the motor-manufacturer and the maker of the air-moving device is difficult to quantify, highly-variable, and is crucial in determining whether the noise emitted in a given application will be defined as a "problem."