Thank you Sir very much for your valuable information. We find in Yogic texts, Svara is used in term of praa.na.
 
As you would know, there is a text available known as "svarodaya". I wonder why it is called svarodaya"saastra, why not praa.nodaya.
 
As per avaialble materials we find in its colophon: iti umaamahe"svarasa.mbaade svarodayaj~naana.m sa.mpuur.nam. After I closely went through available aagamas and puraa.nas I could not find its source text. I would be grateful for further information and help on this subject.
 
 
Once again thanks to all of you for your valuable informations.
 
with Best Regards, 

From: Dipak Bhattacharya <dbhattacharya200498@YAHOO.COM>
To: INDOLOGY@liverpool.ac.uk
Sent: Monday, 8 October 2012 8:53 PM
Subject: [INDOLOGY] Fw: [INDOLOGY] svara as breathing/respiration


----- Forwarded Message -----
From: Dipak Bhattacharya <dbhattacharya200498@yahoo.com>
To: Nivedita Rout <nivi71r@YAHOO.CO.IN>; "INDOLOGY@liverpool.ac.uk" <INDOLOGY@liverpool.ac.uk>
Sent: Monday, 8 October 2012 8:51 PM
Subject: Re: [INDOLOGY] svara as breathing/respiration

In the description of the generation of sound, Pāṇinīyaśikṣā vss 6cd and 7ab state:
The mind hits the bodily fire, that sends the (bodily) wind (=breath), the breath roaming in the breast generates a charming svara.
The place of the wind ie breast seems to indicate that life-breath that is Prāa is meant. Not itself svara it is held responsible for its generation.
Best
DB

From: Nivedita Rout <nivi71r@YAHOO.CO.IN>
To: INDOLOGY@liverpool.ac.uk
Sent: Monday, 8 October 2012 10:25 AM
Subject: [INDOLOGY] svara as breathing/respiration

Respected Scholars,
 
I am looking for the earliest textual references of "svara" used in term of "breathing" apart from Yogic texts.
I find close evidences i.e  "praa.na is svara" in Upanisads.Still I look for it in particular in tantra literature. 
 
Thank you all in advance for your help and suggestions!
Regards,