My ideas on Swara recognition:
Swara recognition is not a thing to be learned, but developed. It's like a little miracle
or a series of little miraculous triumphs.. I don't think you fixate on it to achieve it. You don't try to recognize R1, d2, g3 etc. You just recognize srgmpdns in whatever combination it occurs. You can sense the distance from the previous swara to later know which ri or which ga it is. People who hear swaras hear just ri ga ma in their heads, not r1,g2,m. An understanding of the interval might occur later.
The most important thing in my mind is to LISTEN with focus and intent and discipline. In Carnatic music, as everyone knows, all swaras are relative, and none can be identified without knowing the sound of Sa. Most beginners slip up right there, forgetting it and getting upset that they can't recognize anything. You need to close your eyes and
listen to the sound of the tambura in a concert or in a recording. (It's really loud too these days in concerts
) The tambura goes pa- SA- SA- sa.. The upper sa being double the length of the other two notes makes it easier to identify all three notes. Always stay focused on the sa. This should be done for a few days without worrying about the other swaras, and during all parts of the concert or recording, as much as you can, as long as it is enjoyable and not too tiring. In just a few days, these three notes are fixed in your brain and are readily recognizable. The structure of our songs also adds to making this easily recognizable, and when the song or stanza ends on a note between these two, you think of it as Pa.
The next step would be to choose recordings that are in ragas that are very familiar, with large intervals between swaras, like Mohanam, shudda saveri, madhyamavati, hindolam, valaji and objectively know their arohanam and avarohanam. It would make sense to choose vidwans who do not sing with too many anuswaras or brighas and recordings that are not too fast. A slow alap or the slower part of the alap would be great. Sing the arohanam and avarohanam or think of it before you start listening. I would prefer an instrumental alap too in these early stages, as any syllables that are pronounced may interfere with the connection we need to make between swara sthanas and the swaras. It's a bit like the connection between word and meaning or like touch typing - thinking of the letter f every time we type it with the left index finger and using only the index fingre for the letter F make that connection happen. A pronounced syllable initially interferes with that activity of thinking and obstructs the making of a deep connection..
Once one of these ragas is chosen, the alap or instrumental song must be listened to very regularly with the tambura shruti constantly in your head, along with the awareness of the arohana and avarohana. I feel this would help.. This can be repeated over days with other ragas.
Once you are thrilled with your progress, you can introduce other ragas that are only slightly different from these, like hamsadhwani and distinguish its sound from Mohanam or like malayamarutham and valaji and you will begin to hear the ni of hamsadhwani distinctly because of your familiarity with mohanam's da which is missing, or the ri of Malayamarutham which is an intermediate addition to Valaji's sa-ga. It is important to THINK of these additions / substitutions when they occur by their names: ri or Ni, in the two new ragas.
Shankarabharanam is a great raga to begin with because of the substantial and equal spacing between notes, except for the ni-sa. Kalyani is a great ragam to juxtapose with Shankarabharanam to get a feel for the pratimadhyama.
I don't think one should fixate on which ri and which ga it is, with familiarity and practice and over years, you will be able to distinguish them. It would be impossible to tell them apart at the beginning stage. Also, r2 can be g1, the context is always important. At any given time, you only need to hear ri ga, sa ri ga in your head when you listen to the music.
This is for the basics.. listen more and more and it all gets nicely established and hopefully one day, I will hear "all" the swaras of that item Rsachi talked about, I hear about 70 percent. I don't think fast enough for some of it. I know that if I listened to it a few times, I will get it all, but I want it all to become impossible to miss
.