3 db is nothing, probably less the sound of a needle dropping on a tiled floor.
What is the maximum ammount of Decibals a Human ear can withstand without taking damage? - Yahoo! Answers
0 (N) BEGINNING OF HEARING, A MOSQUITO 10 FEET AWAY, THE EAR DRUM MOVES LESS -REF.1.1990
THAN 1 / 100 THE LENGTH OF AN AIR MOLECULE (N)
3.5 (P) 1E-10 METERS OF MERCURY = 0.0000000001
METERS OF MERCURY
10 (P) ABSOLUTE SILENCE, ATT-BELL LABORATORY “ QUIET ROOM “
13 (P) ORDINARY LIGHT BULB HUM
15 (N) A PIN DROP FROM A HIEGHT OF 1 CENTIMETER AT A DISTANCE OF 1 METER -REF.1.2003
30 (P) TOTALLY QUIET NIGHTIME IN DESERT-IMPOSSIBLE ANYWHERE NEAR CITY
35 (P) ANECHOIC HEARING TEST ROOM -REF.1. 1998
40 A WHISPER, A NORMAL CONVERSATION IS 60 DB, NORMAL SOUND 70 DB -REF.1.1983