GRBAS is the most widely used perceptual voice rating scheme outside North America and the one most voice researchers will expect to find. Five parameters, each rated 0–3, proposed by the Japanese Society of Logopedics and Phoniatrics and popularized through Hirano's 1981 monograph. It is smaller and blunter than CAPE-V and that is exactly why it survives: a four-point ordinal rating on five named parameters is quick, teachable, and comparable across decades of literature.
Use this rather than CAPE-Vr when you are replicating or extending work that used GRBAS, when your raters were trained on it, or when you want the coarser, faster instrument. Use CAPE-Vr when you want pitch and loudness rated explicitly and finer gradations. Rating the same sample on both is legitimate and occasionally informative — the two scales disagree most on breathy-strained voices — but do not treat the parameters as interchangeable: GRBAS Grade is not defined identically to CAPE-V overall severity, and Asthenia has no CAPE-V counterpart at all.
Asthenia is the parameter people skip. It rates weakness — a voice that sounds under-powered, running out of energy, lacking the drive to sustain phonation. It is the mirror image of Strain, and a voice can genuinely show both at different moments in the same sample. Rate it; a systematically blank A column usually means the rater has not internalized the definition.
Ear only. None of these five parameters is visible in a transcript. Listen to a stretch, tag it, and rate what you heard.