Power is measured in Watts, and is the product of voltage times current. Silicon is the basis for semiconductors and it has 4 valence electrons that contribute to bonding atoms together into solid state silicon. Sound waves correspond to pressure fluctuations that alternate above and below atmospheric pressure. AC voltage is a useful way to represent and process acoustic information because it corresponds to a voltage that alternates between positive and negative, with respect to some reference voltage. Resistivity is an intrinsic property, depending upon the atomic structure of the metal and the extent to which electrons are scattered by the lattice of bonded atoms as they respond to an applied voltage across the wire.
Resistance is directly proportional to resistivity.
The other two factors are geometric and can be understood by analogy to the flow of water in a pipe. Suppose a stream is funneled into a pipe. The longer the pipe, the more the stream flow would be inhibited. The larger the opening of the pipe, the less the stream flow would be inhibited. Similarly, the longer a piece of wire, the greater its resistance to current flow, and the larger its cross section, the less its resistance.