The other part of their 'secret' meditation.
The Quan Yin method of the Supreme Master Ching Hai Association consists of two parts, light and sound. Initiates are told to do each part in proportion of 1.5 hours of light and 1 hour of sound.
At the Quan Yin initiation of the group this is what they teach of the sound part of the method:
Sound part of method
Go into a completely squatting position with your elbows resting on your legs, or sitting on with a table with the elbows on the table, then block the ears with the thumbs inserted in them and the palms on head, do not put any fingers on the third eye (that is around the center of the forehead). Concentrate on the third eye and you should then hear some sounds. At the initiation they say don't let anyone see you doing this part of the method and quite often during group meditation initiates would cover themselves with a sheet or blanket while doing it. Ignore any sounds from the left, behind or below as they may be from Ghosts or demons, concentrate only sounds coming from the front, right and above. You'll hear 'heavenly' sounds which would be things like a harp, bells, whistles, flute, bagpipe,etc... To increase the chance of hearing sounds sit in the squat position, another thing you can do to increase the likelihood of success in this method is keeping the left thumb fully inserted while having the right thumb inserted but not fully.
There are 5 levels of which you'll hear sounds from, sounds at each level may include:
5th Level - Trumpet
4th Level - Flute
3rd Level - Harp, guitar
2nd Level - Sea tide sound or temple bells, church bells
1st Level - Bells, wind