Thomas A. Watson invented, but did not patent, the soundproof booth for use in demonstrating the telephone with Alexander Graham Bell in 1877. There are variations of the same concept, including a portable standalone isolation booth, a compact guitar speaker isolation cabinet, or a larger guitar speaker cabinet isolation box. A "gobo panel" achieves the same idea to a much more moderate extent; for example, a drum kit that is too loud in the live room or on stage can have acrylic glass see-through gobo panels placed around it to deflect the sound and keep it from bleeding into the other microphones, allowing more independent control of each instrument channel at the mixing board.