| 摘要 |
<p>Buzzes, rattles or squeaks may be heard in a moving vehicle during use. An apparatus for detecting and identifying such noises and their sources consists of at least one microphone (14) and at least one accelerometer (16) that are installed in the vehicle. The microphone is used to check if a noise is above a detectability threshold. A plurality of characterising features of the signals from the accelerometer (16) are determined by a computer (18), and from these features the nature of the sound source is identified. The features may include the frequency spectrum and its variation with time, and in this case the signals may be analysed by wavelet packet analysis because the sounds are typically of short duration.</p> |
