low- frequency conduction area, although the transmission of low frequencies through the feet is not as efficient as through the seat. The advantage of tactile transducers used for low frequencies is that they allow a listening environment that is not filled with loud low-frequency sound waves in the air. This helps the drummer in a rock music band to monitor their kick drum performance without filling the stage with powerful, loud low-frequency sound from a 15-inch (40 cm) subwoofer monitor and an amplifier, which can "leak" into other drum mics and lower the quality of the sound mix. By not having a large, powerful subwoofer monitor, a bass shaker also enables a drummer to lower the sound pressure levels that they are exposed to during a performance, reducing the risk of hearing damage. For home cinema or video game use, bass shakers help the user avoid disturbing others in nearby apartments or rooms, because even powerful sound effects such as explosion sounds in a war video game or the simulated rumbling of an earthquake in an adventure film will not be heard by others. However, some critics argue that the felt vibrations are disconnected from the auditory experience, and they claim that that music is less satisfying with the "butt shaker" than sound effects. As well, critics have claimed that the bass shaker itself can rattle during loud sound effects, which can distract the listener. World record claims With varying measures upon which to base claims, several subwoofers have been said to be the world's largest, loudest or lowest. Matterhorn The Matterhorn is a subwoofer model completed in March 2007 by Danley Sound Labs in Gainesville, Georgia after a U.S. military request for a loudspeaker that could project infrasonic waves over a distance. The Matterhorn was designed to reproduce a continuous sine wave from 15 to 20 Hz, and generate 94 dB at a distance of , and more than 140 dB for music playback measured at the horn mouth. It can generate a constant 15 Hz sine wave tone at 140 dB for 24 hours a day, seven days a week with extremely low harmonic distortion. The subwoofer has a flat frequency response from 15 to 80 Hz, and is down 3 dB at 12 Hz. It was built within an intermodal container long and square. The container doors swing open to reveal a tapped horn driven by 40