Yes, with loop-back and end-check

The measurement is performed using a physical loop-back, usually connected from output right channel to input right channel.

A pulse is sent through the loop-back before the measurement is performed and it makes it possible to determine the initial time delay correctly.

After the measurement is finished, a pulse is also sent through the loop-back. The time delay between this pulse and the pulse sent before the measurement was started is checked. This end-check is used to detect errors in the measurement caused by non-continuous play or record. The loop-back settings (see below) must be properly set.

For more detailed explanation see the WinMLS User’s Guide in the chapter Measurement 3: Measuring using loop-back.