At about 15 seconds into this song, playing very lightly in the background, you can hear the S.O.S. distress signal in morse code being played as part of the Vah Medoh theme. In morse code, the shorter noises are called 'dits', and the longer ones are 'dahs'. The signal sounds like this.
Turns out this morse code theme is part of every single Divine Beast them. The other three themes have more going on in them while the distress signal is being played, making it harder to hear, but they are indeed present. What an awesome find! Credit goes to Takfloyd over on Reddit. Thanks to Kao for the heads up!