Synchronous averaging for asynchronous sampling data

AbstractThe progress of digital audio technology has enabled the familiar use of products such as CD and DAT in acoustic measurement. For example, a signal reproduced with a CD player is inputted into a subject for measurement and a DAT recorder records its response. However, the sampling cannot be synchronized completely with the input signal, although both nominal sample rates are set up equally, because the player and recorder work independently. The most popular solution is to use software to perform the synchronous addition after converting the recorded signal into the original sampling rate. However, the rate conversion also has an error due to the windowing in the high‐frequency region of the processed signal. This paper proposes a new method for averaging asynchronous sampling data to solve these problems. To evaluate performance, the transfer function of only measuring equipment estimated from asynchronous sampling data was compared with the measurement results in synchronous sampling conditions. Both results agreed within 0.1 dB, so the effectiveness of the new method was confirmed. In measuring the frequency response of a BPF when white noise is introduced, the proposed