动力总成NVH表现形式

动力总成噪声是由于动力总成传递的力、振动和辐射噪声产生的车内噪声，频率范围比较宽广，从20Hz到几千Hz，通常500Hz以内主要由结构 传递，500Hz以上声音传递。其NVH的主要表现形式有以下几种：

Boom: Continuous low frequency sound, 20 - 80 hz ( note: the frequency ranges given here are approximate). This is commonly a pure tone i.e. a sign wave at a specific frequency. 连续的低频噪声，大约20-80Hz的纯音。 

Buzz: High frequency vibration (>50 Hz) {Note-Location needs specification} 大于50Hz的高频振动 。

Clunk: A transient, low frequency, broadband noise. 瞬态的，低频宽带噪声 Drone: Similar to boom but at a higher frequency (100-200 hz range). 同Boom类似，但频率范围在100-200Hz，经常和Ｂｏｏｍ不区分 。

Growl: A broadband noise in the 100-1000 hz range with a noticeable time variation (modulation). 在１００－１０００Ｈｚ之间的宽频噪声，明显随时间波动（调制）。 

Moan: A low amplitude sound in the 80-200 hz range, frequently consisting of one or two tones. ８０－２００Ｈｚ之间低幅值噪声，通常由１－２个纯音组成。

Periods: Peaks in the sound pressure observed as engine rpm increases or decreases. These peaks are usually due to engine mount and accessory resonances. 峰值明显随发动机转速升高或降低，通常由于发动机悬置和附件共振 引起 。

Rattle: The noise due to the random impact of two surfaces. 由于两个面随机撞击产生的噪声 。

Rumble: Rumble is low to mid frequency broadband noise (100 - 500 hz) which varies in amplitude. 中低频的宽带噪声（１００－５００Ｈｚ），幅值是变化的 。

Shake: Low frequency vibration 低于５０Ｈｚ的低频振动 Tick and Hash: Miscellaneous noises with considerable time variation. 随时间变化很大的其它噪声 。

Whine: A mid to high frequency sound (200-2000 hz) consisting of a tone and harmonics. 由纯音和谐次组成的中高频噪声（２００－２０００ＨＺ）。