This class provides for: (a) wired one-way electrical transmission or processing systems for audio signals, (b) Stereophonic systems, which are not elsewhere classified, (c) instrument or process for converting an electrical audio information signal to or from humanly audible form.
(1) Note. A "system" is an assemblage of two or more elements having diverse functions.
(2) Note. An "audio" signal is an electrical signal which represents spoken or other sounds which vary with time, and may be in analog or digital form.
(3) Note. Combinations of a loudspeaker or microphone with another audio signal processing device (e.g., amplifier, filter, etc.) or other circuit (e.g., bias circuit) are classified herein even if the loudspeaker or microphone is included by name only.
(4) Note. Nominal recitation of "audio" is not sufficient to afford classification herein of an invention which would be otherwise classified elsewhere.
LINES WITH OTHER CLASSES
A transducer for conversion of speech or similar sound (e.g., music) to or from a corresponding electrical signal, and the combination of such a transducer with acoustical structure is classified herein (see Subclass References to the Current Class, below). Note that transducer structure combined with circuitry, other than a lead or connector, is classified with the system, either in this class (381), or in an external class for processing an audio signal.
Excluded from this class are two-way wired electrical audio signal transmission systems which are classified elsewhere. Transmissions of pulse signals which do not represent audio signals is classified elsewhere. Multiplex Communication
Systems (except stereophonic multiplex systems) are classified elsewhere. Modulated Carrier Wave Communication Systems and devices are classified elsewhere. Combinations of subject matter of this class with structure of a more comprehensive combination (e.g., Television Set) are classified with the combination. (See References to Other Classes, below.) SEE OR SEARCH THIS CLASS, SUBCLASS:
150+, for a transducer for conversion of speech or similar sound (e.g., music) to or from a corresponding electrical signal, and the combination of such a transducer with acoustical structure.
REFERENCES TO OTHER CLASSES
SEE OR SEARCH CLASS
27, Undertaking,
31, for systems adapted for communication with entombed persons.
73, Measuring and Testing,
584+, for measuring sound waves, especially subclass 585 for audiometers (ear or hearing testing), and subclasses 646+ for measuring sound intensity.
84, Music,
600+, for electronic musical instruments.
178, Telegraphy, for transmissions of pulse signals which do not represent audio signals. (Lines With Other Classes and Within This Class)
181, Acoustics, appropriate subclasses for mechanical audio systems. 330, Amplifiers, for amplifiers not having specific input signals or specific loads.
340, Communications: Electrical, appropriate subclasses for electrical communications in general.
367, Communications, Electrical: Acoustic Wave Systems and Devices,
132, for underwater speech transmission by an acoustic wave; subclasses 140+ for an acoustic transducer not related to speech signal conversion.
369, Dynamic Information Storage or Retrieval, appropriate subclasses for storing and retrieving sound signals.
370, Multiplex Communications, appropriate subclasses for multiplex communications and for multiplex communication systems (except stereophonic multiplex systems). (Lines With Other Classes and Within This Class)
375, Pulse or Digital Communications, for transmissions of pulse signals which do not represent audio signals. (Lines With Other Classes and Within This Class)
379, Telephonic Communications, for two-way wired electrical audio signal transmission systems. (Lines With Other Classes and Within This Class)
455, Telecommunications, appropriate subclasses for modulated carrier wave speech communications, and for modulated carrier wave communication systems and devices. (Lines With Other Classes and Within This Class,
150+, for high temperature (Tc 30 K) superconducting devices, and particularly subclasses 202+ for electric communication system containing transmitter or receiver of pulse, digital, or electromagnetic radio, television, or radar wave form. 600, Surgery,
559, for audiometers (ear or testing by auditory stimulus).
623, Prosthesis (i.e., Artificial Body Members), Parts Thereof, or Aids and Accessories Therefor,
9, for mechanical artificial larynxes.
704, Data Processing: Speech Signal Processing, Linguistics, Language Translation, and Audio Compression/Decompression,
200+, for speech signal processing using a computer.