The secret of success in spiritual life

One has to receive the transcendental sound from the right source, accept it as a reality and prosecute the direction without hesitation. The secret of success is to receive the sound from the right source of a bona fide spiritual master. Mundane manufactured sound has no potency, and as such, seemingly transcendental sound received from an unauthorized person also has no potency.
SB 2.9.8 purport