The above image shows the slow shift up in frequency of several of the embedded tones. Total length of time displayed is about 86 seconds. Oldest time is to the left, newest is to the right. The sample rate is too slow to detect the individual pulses. Each vertical red tick along the bottom is 10 seconds of time.

The curser is placed over the second tone up, near the right side of the image to measure the frequency at the end of the scan. The frequency is 1102.0 Hz, showing an increase in this case of about 19.5 Hz in a period of 86 seconds.