What exactly do we mean by the term 'deep meditation'?

Question

When we say that a person is in deep meditation then what exactly do we mean:

1. Is the person still aware of what is going around him, like he can hear the various sounds be it anything?

2. He is not aware of anything apart from his breath?

3. He is not aware of anything at all?

4. None of the above, it is something else?

Answer 1

DhyAna Lakshana (sign of meditation) is mentioned very briefly in the following verse by Lord Shiva:

yathA nimilane kAle prapancha naiva pasyati |
Tathaiva unmilanehapi syAdetad dhyAnasya lakshanam ||

Just like the person, who has his eyes closed, can not see the outer world, in a similar manner, a person who is engrossed in meditation, can't see the same with even his eyes open - and this is the sign of DhyAnam.

KulArnavara Tantram 9.19

So, if a meditating person has kept his eyes open, but still he can not see anything around, then it is to be understood that he is properly meditating. So, a properly meditating person is not aware of the existence of the world around him.

And, when meditation reaches it's highest stage, that is called the SamAdhi stage and the signs of SamAdhi are slightly different from what is mentioned above.

Lord Shiva mentions the following signs:

Na shrinoti na chAghrAti na sprishati na pasyati |
Na jAnAti sukham dukkham na cha samlipyate manah ||
Na chApi kinchit jAnAti na cha vrudhyAti kAshthavat |
Evam shive vilinAtmA samAdistha ihochyate ||

One who does not hear, does not [perceive] smell, does not touch, does not see, does not feel either pain or pleasure, whose mind is not attached [to anything], who is just like a piece of wood, who does not understand or know anything --- completely merged in Shiva know such a person to be in SamAdhi.

19.13,14

Answer 2

According to Patanjali, the stages of yoga are yama Niyama Asana Pranayaama Pratyahaara Dhaaranaa Dhyana and Samadhi. Pratyahara means withdrawal of the mind from external objects. The next stage is dharana, and then Dhyana. Patanjali's concept of dhyana has been explained by Swami Vivekananda as follows:

In order to reach the superconscious state in a scientific manner it is necessary to pass through the various steps of Raja-Yoga I have been teaching. After Pratyâhâra and Dhâranâ, we come to Dhyâna, meditation. When the mind has been trained to remain fixed on a certain internal or external location, there comes to it the power of flowing in an unbroken current, as it were, towards that point. This state is called Dhyana. When one has so intensified the power of Dhyana as to be able to reject the external part of perception and remain meditating only on the internal part, the meaning, that state is called Samadhi. The three — Dharana, Dhyana, and Samadhi — together, are called Samyama. That is, if the mind can first concentrate upon an object, and then is able to continue in that concentration for a length of time, and then, by continued concentration, to dwell only on the internal part of the perception of which the object was the effect, everything comes under the control of such a mind.

Following Patanjali, He explains the concept of dhyana further as

. An unbroken flow of knowledge in that object is Dhyâna.

The mind tries to think of one object, to hold itself to one particular spot, as the top of the head, the heart, etc., and if the mind succeeds in receiving the sensations only through that part of the body, and through no other part, that would be Dharana, and when the mind succeeds in keeping itself in that state for some time, it is called Dhyana (mediation).

So in deep meditation there should be no awareness of the external world as the mind is immersed in its own object of thought. Swamiji's biography has many such examples since His childhood.

Answer 3

Meditation is the very delicate art of doing nothing, it is the perfect relaxation. Any effort you put in will get you out of meditation. Its like sleeping, as long as you are asleep you do not know, but as soon as you get aware that you are sleeping, you are awake.

It is best not to analyze the experience or share the experience with others, a good(deep) or bad meditation is something that we are labeling to our experience, it may have been deep even though you felt otherwise.

Sri Sri Ravishankar says that there are three stages of meditation.

“When you go deep into that empty space that you are feeling in meditation, three 
 things happen:

 1) At the beginning of the meditation, you don’t see anything, you just see 
 emptiness, but when you put attention there when you continue there,

 2) then you start feeling the vibrations. This is called spandana, when you feel 
 some vibrations, some sensations,

 3) and then that vibration becomes light.

 So the first step is really nothing but relaxation, and then from there feeling the 
 energy, sensations, vibrations, and then it becomes light.”

So its best to let the experience be and trust the practice, the practice given by a guru has the grace that eventually guides you. And if you do not have a guru, don't worry s/he will find you when it's time.