voice sample

No for both questions.

With due respect, I doubt the correctness of my learned frined Dr. Tripathi.

My answer is that the police cannot take samples without lodging f.i.r. and intimated about the f.i.r. to the area magistrate.

Dear prabhakar ji ! where is point of diference between you and me !

the question is without the f.i.r being filed can they take voice samples ? answer - No. this is exactly what you are saying.

intimation to court is necessary but approval to take evidence is no necessary.

i am still not clear sir,

u mean to say that first the F.I.R must be lodged, and then court permission is needed for taking voice samples during investigation.

plz explain in little detail sir,

Sir, only if complaint is filed by a person, then can the police take voice samples during investigation or not. 

No. Only on the basis of the complaint, police cannot take voice samples.  If they take such a step, it is illegal.  In such a situation, you have to approach the high court under writ jurisdiction to take action against the erring police officials.

Yes he can file a writ petition as action of police in this matter amounts to torture and violation of personal liberty guaranteed under Art. 21 of the Constitution of India.

Dear Sirs, under Section 156 of Cr. PC., (Police officer's power to investigate cognizable case).  (1) Any officer in charge of a police station may, without the order of a Magistrate, investigate any cognizable case which a court having jurisdiction over the local area within the limits of such station would have power to inquire into or try ....

(2)  No proceeding of a police officer in any such case shall at any stage be called in question on the ground that the case was one which such officer was not empowered under this section to investigate.

If the voice recording was done as a part of the investigation, no prior permission is required.  

so even on the basis of complaint the police can take voice samples,

there is no need if F.I.R,

is it correct

what is the difference between a complaint and F.I.R.

when police refused to lodge an FIR, then Complaint is made to the magistrate

Find attached a  Delhi High Court judgment on this aspect