Abstract: A headset includes a speaker, such as a side firing dipole speaker. The headset includes a front chamber that receives sound waves from a first side of the speaker and a rear chamber that receives sound waves from a second side of the speaker. A control leak channel connects the front chamber and the rear chamber. An acoustic mesh may be located within the control leak channel. The speaker configuration is configured to reduce total harmonic distortion of the speaker, particularly in ranges such as 3-6 kHz, while maintaining the broadband efficiency of the speaker.

Abstract: A headset includes a speaker, such as a side firing dipole speaker. The headset includes a front chamber that receives sound waves from a first side of the speaker and a rear chamber that receives sound waves from a second side of the speaker. A control leak channel connects the front chamber and the rear chamber. An acoustic mesh may be located within the control leak channel. The speaker configuration is configured to reduce total harmonic distortion of the speaker, particularly in ranges such as 3-6 kHz, while maintaining the broadband efficiency of the speaker.

Abstract: A package advantageously to be mounted within the housing of a coin telephone permits the telephone set to exhibit a jack to which a personal computer may be connected without danger of the jack being used for fraudulent purposes by normally maintaining the jack isolated from the central office conductors. A local battery powers a microprocessor which senses when a modem is connected to the jack. The microprocessor controls the connection to the central office conductors which then supply power for the further continuous monitoring of the conductors to determine whether the connection is being used legitimately or whether tones are applied at the jack to simulate the deposit of coins. In addition, the jack is disconnected from the central office conductors during the time that the initial rate test is being performed by the central office.