Replaceable snap-together wires, headphones, headband and plug comprise a modular stereo headphone apparatus. Sealed headphones are provided with walled receptacles to receive mating removable clips secured to the ends of connecting wires. Each clip is molded to the wire insulation and around the wire ends which protrude slightly beyond the clip. Each clip is provided with a protruding movable lever arm with an indent for mating with a protrusion inside a receptacle shaped to fit the clip. Wires from the sound system within each headphone protrude through each receptacle wall to mate in proper polarity with wires in the inserted clip. A flexible headband is provided along its length with either a groove or tabs to receive a headphone connecting wire removably secured to the headband. At each headband end a sleeve receives a protrusion from one headphone adjustably secured to the headband with a spring-loaded pin in the sleeve engaging notches in the headphone protrusion. A male plug for the sound system has an adapter with one or two receptacles for receiving one or two clip ended wires from one or two headphone sets.

The invention is an improved amplification system for guitars that does not require electrical energy. The system is self-contained and intended for use by the guitarist to listen to the music that he produces on an electrical-type guitar without connection to an electronic-type amplification system. The guitarist can use it during practice or for personal enjoyment without the sound reaching others in the nearby vicinity of the guitarist. The system provides a pick-up piece on the guitar, a connecting pick-up piece for the main sound transmittal tubes, sound transmittal tubes, and an insulated headset.

A car radio system includes a car radio and at least two speakers connected to the car radio. The system can be used by only some of the vehicle occupants without disturbing the other occupants by providing at least one of the speakers with a jack for connecting a headset plug and with a switch that can be used to deactivate playback via the speakers.

The headset comprises left and right elongate ear pieces having respective first ends to receive ear tips and respective, interconnected second ends. Each ear piece includes a one-piece elongate body made of flexible and resilient material and curved outwardly to skirt round the user's head when the ear tips are applied to a user's ears. The elongate body is formed with a first length of smaller cross section and therefore of greater flexibility proximate the second end of the corresponding ear piece and with a second length of lower flexibility situated between that first length and the corresponding ear tip. Bending of the elongate bodies when the ear pieces are spread apart is therefore concentrated in the first lengths and pressure applied to the user's ears by the ear tips is mainly produced by the bent first lengths and transmitted to the ear tips through the second lengths of lower flexibility. The elongate ear pieces have respective second end sections assembled laterally adjacent to each other, and a threaded sleeve is mounted on these laterally adjacent second end sections and is rotated and displaced longitudinally to adjust the level of pressure applied to the user's ears by the ear tips.

A headset includes two earpieces. One earpiece acts as a microphone, and the other earpiece acts as an earphone. Isolated from background noise and vibrations due to bone conduction, the microphone earpieces convert voice sounds from the air column in the external ear canal into electrical signals. Other embodiments of the invention address feedback problems and achieve improved performance relative to existing full duplex communication devices. In another embodiment of the invention a headset includes a band having opposite ends that extend in a forward direction from the two earpieces. The band then either extends downwardly or backwards.