(A) Systems, processes and instruments for the two-way electrical transmission of intelligible audio information having arbitrary content over a link including an electrical conductor, between spaced apart locations, so as to enable conversation therebetween, and intended for the private use of a listener or a group of listeners. The term "intelligible" used above is intended to include the capability for transmission of speech or the like (e.g., music), rather than restriction to a specified audible signal, such as a bell or buzzer.
(B) Switching, signalling or signal transmission peculiar to, or specified as for a telephone or a telephone system, except for multiplex communications as indicated in Lines With Other Classes and Within This Class, below.
(C) Subsystems, elements and adjuncts peculiar to such transmission and not provided for elsewhere.
LINES WITH OTHER CLASSES
(1) Bi-directional audio communication is normally a duplex arrangement, and simultaneous audio transmission of a single conversation is in this class (379) and excluded from Class 370, Multiplex Communications, in the absence of some other particular multiplexing technique.
(2) With exception of voice signal duplexing as pointed out in (1) above, subject matter including multiplexing, particularly involving plural conversations, regardless of recitation of telephone limitations, is excluded from this class (379) and is classified elsewhere.
(3) Audible signalling for call alerting, or producing a signal having other specific content, such as bells, buzzers, etc., are classified elsewhere, even if nominally characterized as used in a telephone. (4) Electromagnetic switches for automatic telephone switching type, per se, are classified elsewhere.
(5) Electrical connectors merely nominally characterized as for telephones, in the absence of additional telephone structure are classified elsewhere.
(6) Named communications or telecommunications networks absent recitation of telephone or voice limitation are not classifiable herein.
(7) The following terms when used in a communication system or instrument are considered to specify telephone equipment except as specified in (2) above with respect to multiplexing or in class or subclass search notes: dial tone - off-hook, handset - on-hook, hookswitch - ringback, howler - sidetone, intercom - switchboard, key set - switchhook, telephone line (used with switching system), tip and ring (leads)
RELATIONSHIP TO OTHER SPEECH COMMUNICATIONS CLASSES
This class (379) requires the capability for two-way spoken communications, or specified used of a telephone line, and subsystems peculiar to either of the above.
A mechanical telephone is classified elsewhere. See References to Other Classes, below.
All speech or telephone equipment which conceals message content despite interception or unauthorized reception of a telephone signal is classified elsewhere. See References to Other Classes, below.
Electrical speech processing system and apparatus, including for example, such systems as, megaphones, public address systems and hearing aids; and transducers such as microphones, earphones or loudspeakers and also includes either of a telephone microphone or receiver are classified elsewhere. See References to Other Classes, below.
Audio signal telecommunications by a modulated carrier wave not having telephone land line structure or limitations is classified elsewhere. See References to Other Classes, below.
SEE OR SEARCH THIS CLASS, SUBCLASS:
1, through 36, for observation, measuring, or testing. 37, through 51, for coin-free paystation, emergency, or alarm equipment.
52, for handicapped user.
55.1, through 56.3, for wireless or carrier link.
67.1, through 88.28, for voice signal storage.
90, through 110, for composite system or terminal.
111, through 142, for usage measurement or display.
143, through 155, for paystations.
156, through 187, for key, private or party systems.
188, through 200, for call or terminal limiting.
201, through 218, for special services.
219, through 332, for switch telephone network. 333, through 349, for network component systems.
350, through 386, for supervisory or control signalling.
387, through 418, for substation or line circuitry or component.
419, through 456, for terminal structure or accessory.
457, for miscellaneous.
REFERENCES TO OTHER CLASSES
SEE OR SEARCH CLASS
181, Acoustics, includes a mechanical telephone.
335, Electricity: Magnetically Operated Switches, Magnets, and Electromagnets, for electromagnetic switches for automatic telephone switching type, per se.
340, Communications: Electrical, for audible signalling for call alerting, or producing a signal having other specific content, such as bells, buzzers, etc., even if nominally characterized as used in a telephone.
370, Multiplex Communications, for subject matter including multiplexing, particularly involving plural conversations, regardless of recitation of telephone limitations;
276+, for duplex transmission. 380, Cryptography, includes all speech or telephone equipment which conceals message content despite interception or unauthorized reception of a telephone signal.
381, Electrical Audio Signal Processing and Systems is a generic electrical speech processing system and apparatus class and includes, for example, such systems as, megaphones, public address systems and hearing aids; and transducers such as microphones, earphones or loudspeakers and also includes either of a telephone microphone or receiver, but not their combination as in a handset.
439, Electrical Connectors, for electrical connectors merely nominally characterized as for telephones, in the absence of additional telephone structure.
455, includes audio signal telecommunications by a modulated carrier wave not having telephone land line structure or limitations.
GLOSSARY:
BI-DIRECTIONAL
Capable of use, particularly in transmitting information in two opposite directions. Additionally, when used to describe an audio transducer, capable of conversion of sound both to and from electrical signal variations.
CALL ADDRESS SIGNAL
An electrical representation of a called terminal designation (i.e., telephone number) which controls switching apparatus to establish a connection from a calling terminal.
DIALING
Generating a call address signal. Although a dial is a rotary pulse generating switch, the term dialing is sometimes used generically as in the terms "tone dialing" and "resistance dialing". SUBSCRIBER
Telephone user or service location.
SUBSCRIBER
Telephone circuitry or instruments at subscriber location.
TELEPHONE
An instrument, known as a user terminal set, containing an audio reproducer, and a speech-to-electricity transducer. An obsolete usage of this term (telephone) is broad enough to include a microphone or reproducer; however, a microphone or reproducer, per se, is classified in Class 381.