The or width) of a sound wave determines its or pitch).

Sound waves are longitudinal mechanical waves, that is, they depend on a medium to propagate.

Among the characteristics of a sound wave, it is the amplitude, that is the degree of movement of the molecules of the medium in which the wave propagates.  

Depending on how high this amplitude is, the sound will be louder.

1. height

2. loudness

current and voltage can both be different in different parts of a circuit so it matters where you place the ammeter and voltmete

c. magnitude and direction