How do you determine the tone quality of a singer’s voice?

Voice is the major investment of the singer that fetches the popularity and earning for his/her life. Singers obviously use their voices in very special ways, influenced by training and esthetic values (self learning and imagination) that make their voice appealing and suitable for singing a particular style of music. The various tone quality of a singer's voice can be determined as follows: Six essential requirements for a good singing voice:- (1) `Sraavaka' is explained as loudness or carrier of the voice, which can be heard from a long distance. (2) The voice that is loud and pleasing with out any wobble is called `ghana'. (3) The voice which does not sound harsh though loud, is described as `snigdha'. This also refers to the `fluency' of producing the notes of high octaves. (4) The voice that is pleasant at high notes is called `madhura'. (5) `avadhanavan' is explained as a voice that is neither too loud nor too soft. (6) `tristhanashobha' is that voice which is pleasant in producing the notes of all the three `sthanaas' (equivalent of registers). Requirement and merits of the singing voice (1) taara (sweetness in the high octaves). (2) anudhvani (rich on account of harmonics). (3) madhuryam (sweetness). (4) raktih (attractive). (5) gambhiryam (Full or loud). (6) mardavaih (beautiful). (7) ganata (rich). (8) kanthih (smooth and bright) read less