|  | G |
SECTION G — PHYSICS

|  | G |
Note(s) In this section, the following term is used with the meaning indicated: "variable" (as a noun) means a feature or property (e.g., a dimension, a physical condition such as temperature, a quality such as density or colour) which, in respect of a particular entity (e.g., an object, a quantity of a substance, a beam of light) and at a particular instant, is capable of being measured; the variable may change, so that its numerical expression may assume different values at different times, in different conditions or in individual cases, but may be constant in respect of a particular entity in certain conditions or for practical purposes (e.g., the length of a bar may be regarded as constant for many purposes). Attention is drawn to the definitions of terms or expressions used, appearing in the notes of several of the classes in this section, in particular those of "measuring" in class Fulltext... Hierarchy... Expanded...G01 and "control" and "regulation" in class Fulltext... Hierarchy... Expanded...G05. Classification in this section may present more difficulty than in other sections, because the distinction between different fields of use rests to a considerable extent on differences in the intention of the user rather than on any constructional differences or differences in the manner of use, and because the subjects dealt with are often in effect systems or combinations, which have features or parts in common, rather than "things", which are readily distinguishable as a whole. For example, information (e.g., a set of figures) may be displayed for the purpose of education or advertising (Fulltext... Hierarchy... Expanded...G09), for enabling the result of a measurement to be known (Fulltext... Hierarchy... Expanded...G01), for signalling the information to a distant point or for giving information which has been signalled from a distant point (Fulltext... Hierarchy... Expanded...G08). The words used to describe the purpose depend on features that may be irrelevant to the form of the apparatus concerned, for example, such features as the desired effect on the person who sees the display, or whether the display is controlled from a remote point. Again, a device which responds to some change in a condition, e.g., in the pressure of a fluid, may be used, without modification of the device itself, to give information about the pressure (Fulltext... Hierarchy... Expanded...G01L) or about some other condition linked to the pressure (another subclass of class Fulltext... Hierarchy... Expanded...G01, e.g., Fulltext... Hierarchy... Expanded...G01K for temperature), to make a record of the pressure or of its occurrence (Fulltext... Hierarchy... Expanded...G07C), to give an alarm (Fulltext... Hierarchy... Expanded...G08B), or to control another apparatus (Fulltext... Hierarchy... Expanded...G05). The classification scheme is intended to enable things of a similar nature (as indicated above) to be classified together. It is therefore particularly necessary for the real nature of any technical subject to be decided before it can be properly classified.

INSTRUMENTS

|  | G10 |
MUSICAL INSTRUMENTS; ACOUSTICS

|  | G10 |
Note(s) This class covers all sound-emitting devices, in general, whether or not they may be considered as being musical. In this class, the following expression is used with the meaning indicated: "musical instrument" does not exclude devices emitting a single sound signal. The following Class Index is given in place of subclass indexes, to show the grouping of the elaborations belonging to different subclasses, under the following three fundamental types: wind instruments; string instruments; percussion instruments, which relate clearly to the majority of instruments. There are of course some instruments of which the principle of operation belongs less clearly to one of the three types mentioned in Note (3). They correspond to groups Fulltext... Hierarchy... Expanded...G10D 17/00 or Fulltext... Hierarchy... Expanded...G10K 7/00, Fulltext... Hierarchy... Expanded...G10K 9/00 or Fulltext... Hierarchy... Expanded...G10K 15/04, all the other groups normally finding a definite place.

|  | G10 |
Class index
ACOUSTICS; OPERATIONS ON SOUND WAVES |
Speech analysis or synthesis; speech recognition | G10L
Methods or devices for transmission of sound or protection against sound, not otherwise provided for | G10K 11/00, G10K 13/00
Acoustics not otherwise provided for | G10K 15/00
WIND INSTRUMENTS |
General features; details, accessories | G10D 7/00; G10D 9/00
Organs, harmoniums, or similar instruments | G10B 1/00, G10B 3/00
Accordions, concertinas, or similar instruments; other types of instruments | G10D 11/00; G10D 7/00
Whistles; sirens; horns | G10K 5/00; G10K 7/00; G10K 9/00
STRING INSTRUMENTS |
General features; details, accessories | G10D 1/00; G10D 3/00
Pianos, similar instruments; tools and methods for making or maintenance | G10C 1/00, G10C 3/00; G10C 9/00
Other types of instruments | G10D 1/00
PERCUSSION INSTRUMENTS |
Bells, rattles, or similar instruments | G10K 1/00, G10K 3/00
Other instruments | G10D 13/00
OTHER PARTICULAR DEVICES: DEVICES USING UNDEFINED PRINCIPLES; COMBINATIONS OF INSTRUMENTS; MUSIC ACCESSORIES |
Electrophonic musical instruments | G10H
Automatic musical instruments | G10F
Sirens; devices with vibrators | G10K 7/00; G10K 9/00
Combinations: of pianos with other instruments; of other instruments | G10C 5/00; G10D 15/00
Music accessories | G10G
INSTRUMENTS NOT OTHERWISE PROVIDED FOR | G10D 17/00

|  | G10L |
SPEECH ANALYSIS OR SYNTHESIS; SPEECH RECOGNITION (sound input/output for computers Fulltext... Hierarchy... Expanded...G06F 3/16; digital data processing methods or equipment specially adapted for handling natural language data Fulltext... Hierarchy... Expanded...G06F 17/20; teaching or communicating with the blind, deaf or mute Fulltext... Hierarchy... Expanded...G09B 21/00; telephonic communication Fulltext... Hierarchy... Expanded...H04M) [4]

P:40 |  | G10L 11/00 |
Determination or detection of speech characteristics not restricted to a single one of groups Fulltext... Hierarchy... Expanded...Fulltext... Hierarchy... Expanded...G10L 15/00-G10L 21/00 [7]

|  | G10L 11/02 |
· | Detection of presence or absence of speech signals (switching of direction of transmission by voice frequency in two-way loud-speaking telephone systems Fulltext... Hierarchy... Expanded...H04M 9/10) [7]

|  | G10L 11/04 |
· | Pitch determination of speech signals [7]

|  | G10L 11/06 |
· | Discriminating between voiced and unvoiced parts of speech signals (Fulltext... Hierarchy... Expanded...G10L 11/04 takes precedence) [7]

P:50 |  | G10L 13/00 |
Speech synthesis; Text to speech systems (electrophonic musical instruments Fulltext... Hierarchy... Expanded...G10H) [7]

|  | G10L 13/02 |
· | Methods for producing synthetic speech; Speech synthesisers [7]

|  | G10L 13/04 |
· · | Details of speech synthesis systems, e.g. synthesiser structure, memory management [7]

|  | G10L 13/06 |
· | Elementary speech units used in speech synthesisers; Concatenation rules [7]

|  | G10L 13/08 |
· | Text analysis or generation of parameters for speech synthesis out of text, e.g. grapheme to phoneme translation, prosody generation, stress or intonation determination [7]

P:10 |  | G10L 15/00 |
Speech recognition (Fulltext... Hierarchy... Expanded...G10L 17/00 takes precedence) [7]

|  | G10L 15/02 |
· | Feature extraction for speech recognition; Selection of recognition unit [7]

|  | G10L 15/04 |
· | Segmentation or word limit detection [7]

|  | G10L 15/06 |
· | Creation of reference templates; Training of speech recognition systems, e.g. adaptation to the characteristics of the speaker's voice (Fulltext... Hierarchy... Expanded...G10L 15/14 takes precedence) [7]

|  | G10L 15/08 |
· | Speech classification or search (pattern recognition Fulltext... Hierarchy... Expanded...G06K 9/00) [7]

|  | G10L 15/10 |
· · | using distance or distortion measures between unknown speech and reference templates [7]

|  | G10L 15/12 |
· · | using dynamic programming techniques, e.g. Dynamic Time Warping (DTW) [7]

|  | G10L 15/14 |
· · | using statistical models, e.g. Hidden Markov Models (HMM) (Fulltext... Hierarchy... Expanded...G10L 15/18 takes precedence) [7]

|  | G10L 15/16 |
· · | using artificial neural networks [7]

|  | G10L 15/18 |
· · | using natural language modelling [7]

|  | G10L 15/20 |
· | Speech recognition techniques specially adapted for robustness in adverse environments, e.g. in noise, of stress induced speech (Fulltext... Hierarchy... Expanded...G10L 21/02 takes precedence) [7]

|  | G10L 15/22 |
· | Procedures used during a speech recognition process, e.g. man-machine dialog [7]

|  | G10L 15/24 |
· | Speech recognition using non-acoustical features, e.g. position of the lips [7]

|  | G10L 15/26 |
· | Speech to text systems (Fulltext... Hierarchy... Expanded...G10L 15/08 takes precedence) [7]

|  | G10L 15/28 |
· | Constructional details of speech recognition systems [7]

P:0 |  | G10L 17/00 |
Speaker identification or verification [7]

P:20 |  | G10L 19/00 |
Speech analysis-synthesis techniques for redundancy reduction, e.g. in vocoders; Coding or decoding of speech [7]

|  | G10L 19/02 |
· | using spectral analysis, e.g. transform vocoders, subband vocoders [7]

|  | G10L 19/04 |
· | using predictive techniques [7]

|  | G10L 19/06 |
· · | Determination or coding of the spectral characteristics, e.g. of the short term prediction coefficients [7]

|  | G10L 19/08 |
· · | Determination or coding of the excitation function; Determination or coding of the long-term prediction parameters [7]

|  | G10L 19/10 |
· · · | Determination or coding of a multipulse excitation [7]

|  | G10L 19/12 |
· · · | Determination or coding of a code excitation, e.g. in code excited linear prediction (CELP) vocoders [7]

|  | G10L 19/14 |
· · | Details not provided for in groups Fulltext... Hierarchy... Expanded...Fulltext... Hierarchy... Expanded...G10L 19/06-G10L 19/12, e.g. gain coding, post filtering design, vocoder structure [7]

P:30 |  | G10L 21/00 |
Processing of the speech signal to produce another audible or non-audible signal, e.g. visual, tactile, in order to modify its quality or its intelligibility (Fulltext... Hierarchy... Expanded...G10L 19/00 takes precedence) [7]

|  | G10L 21/02 |
· | Speech enhancement, e.g. noise reduction, echo cancellation (echo suppression in hand-free telephones Fulltext... Hierarchy... Expanded...H04M 9/08; hearing aids Fulltext... Hierarchy... Expanded...H04R 25/00) [7]

|  | G10L 21/04 |
· | Time compression or expansion [7]

|  | G10L 21/06 |
· | Transformation of speech into a non-audible representation, e.g. speech visualisation, speech processing for tactile aids (Fulltext... Hierarchy... Expanded...G10L 15/26 takes precedence) [7]