Condenser microphones dominate modern audio because they convert sound to electrical signals efficiently.

Evidence

Many conversion principles have been applied in microphones, but many of them, for example the carbon microphones used earlier in telephones, have become obsolete. The most important technology nowadays is the condenser microphone and its variants. Figure 4.2 illustrates the basic physical principle and a typical construction principle of a high-quality condenser microphone used for acoustic measurements and research purposes. The sound pressure variations in the air make one electrode of the condenser move while the other is kept fixed. If an electric charge is present between the electrodes, a change in distance between the electrodes will change the voltage between the electrodes. When this weak voltage signal is amplified inside the same microphone unit, the signal can be fed through a cable to audio equipment over reasonable distances. — Ville Pulkki, Matti Karjalainen, Communication Acoustics- An…, 482

Categorization

• DEFINE: Explains the operating principle of condenser microphones: moving electrode changes capacitance and thus voltage.
• corroborated: 2 independent passages support this claim — Ville Pulkki, Matti Karjalainen, Communication Acoustics- An…, 482