Contact mikes are popular in audio recording industries as they offer crystal clear audio. Sometimes, people use other terms or synonyms for "contact mike" such as a piezo microphone, a vibration sensor, or a pick-up. Piezo microphones are technically similar to contact mikes, and are also used to amplify sound with precise accuracy. Vibration sensors are used in applications like mechanical engineering, and are used to detect and measure vibrations in machines. Conversely, pickups come in a variety of types and are used to pick up the sound of an instrument. So, depending on the context, there are several options for referring to contact mikes or similar recording equipment.