Testing of hands-free devices
When evaluating the acoustic performance of hands-free communication devices, it is important to take into consideration the surroundings, as well as the acoustic influence of the head and body.
In addition to traditional parameters for characterization of communication devices, such as frequency response, loudness rating and directivity response, it is necessary to determine transmission quality in the presence of background noise, switching, and echo cancelling, as these are known to have close correlation with the audio performance and perceived quality of the reproduction of the human voice of hands-free equipment.
For testing hands-free devices, we suggest a system that simulates real life communication situations as closely as possible, without letting the physical presence of a human interfere with the measurements. The system consists of a HATS with ear and mouth simulators, a measurement front end and the PULSE-based Voice Testing Software for Hands-free-equipment Type 7909-NS1. The software has capabilities for both data acquisition and data analysis, according to standards set by VDA (Verband der Automobilindustrie). This configuration can be used both in a lab setting and for in-vehicle testing of audio performance.