Anahata sounds? Perhaps the Conch? Ocean sound
Anahata sounds are the mystic sounds heard by the Yogin during his meditation. It is a sign of the purification of Nadis. Some students can clearly hear it through any one of the ears and some by both the ears. There are loud as well as subtle sounds. From the loud, one will have to contemplate on the subtle and from the subtle to the subtler. Beginners can hear the sound only when the ears are closed. Advanced students can concentrate on the Anahata sound even without closing the ears. Anahata sound is also termed Omkara Dhvani. They proceed from the Anahata centre of the Sushumna Nadi.
Sit in your usual Asana. Close the ears with the thumbs. Hear and minutely observe the internal sound through the ears. The sound that you hear from within will make you deaf to all external sounds. Close the eyes also. In the beginning of your practice, you will hear many loud sounds. Later on they are heard in a mild way. The mind having at first concentrated itself on any one sound fixes firmly to that and is absorbed in it. The mind becoming insensible to the external impressions, becomes one with the sound as milk with water and then becomes rapidly absorbed in Chidakasa. Just as the bee drinking the honey alone does not care for the odour so also the Chitta, which is always absorbed in the inner sound, does not long for sensual objects, as it is bound by the sweet smell or Nada and has abandoned its flitting nature.
The sound proceeding from Pranava Nada, which is Brahman, is of the nature of effulgence. The mind gets absorbed in it. The mind exists so long as there is sound, but with its cessation, there is that state termed Turiya. It is the supreme state. It is the Unmani state. The mind gets absorbed along with Prana by constant concentration upon Nada. The body appears to be a log of wood and it does not feel heat or cold, joy or sorrow. Different kinds of sounds proceed from the heart (Anahata sounds).
Nada that is heard through the ears is of ten kinds. The first is the sound ‘Chini’ (like the pronunciation of the word); the second is ‘Chini-chini’; the third is the sound of a bell; the fourth is that of a conch; the fifth is that of a lute; the sixth is the sound of cymbals; the seventh is the tune of a flute; the eighth is the voice of a drum (Bheri); the ninth is the sound of a double-drum (Mridanga); and the tenth is the sound of thunder.
You cannot expect the sound immediately after you close your ears. You should concentrate and keep your mind one-pointed. The particular sound that you hear today, you may not hear every day. But you will hear any one of the ten Anahata sounds.
The description given above is Laya through Nada, Anahata sound. In the same manner, Laya can be effected by concentration at the tip of the nose (Nasikagra Drishti), at the space between the two eyebrows (Bhrumadhya Drishti), meditation on the five Tattvas, on Soham Mantra, Aham Brahma Asmi, Tat Tvam Asi Mahavakyas and other methods also.