EP1850639A1 - Systems for generating multiple audio signals from at least one audio signal - Google Patents

Abstract

The device evaluates manual or technically measured, determined angles of mono signals, sound source and microphone main axis, and calculates amplification factors (PM, PB) and delay times (LA, LB) depending on the angles of the signals. The mono signals are amplified to the amplification factor (PM) to receive a main signal. The mono signals are delayed at the delay times, where the delayed mono signals are amplified to the amplification factor (PB). The main signal and a side signal are converted into a stereo signal. Independent claims are also included for the following: (1) a method for stereophonorising a mono signal (2) a method for producing a mono signal.

Description

I. Subject of the invention

The invention relates to signal systems and apparatus for the conversion of corresponding signals. The invention is explained with reference to various transducer systems and other practical examples.

II. Brief description of the prior art

• "Es ist grundsätzlich nicht möglich, aus einer Monoaufnahme ein Stereosignal zu gewinnen, das mit einem wirklichen Stereosignal vergleichbar wäre." (Dickreiter, 1987)

The prior art can be illustrated by the problem solved in the following application example, the recovery of a pseudo-stereophonic signal from a single mono signal, with Dickreiter as follows:

• "It's basically not possible to get a mono from a stereo signal that would be like a real stereo signal." (Dickreiter, 1987)

This theorem is supposedly valid since the work of Blumlein.

JP 11146499 A (Tatsuya & Masao, 1999 ) stays in the targeted Use of phase shift in the dependence on frequencies in the sense of the above quotation Dickreiters, scientifically limited, limited (" To provide a pseudo stereo circuit in simple configuration. "- Tatsuya & Masao, 1999 ), and, clearly delimited, does not constitute a specific technical implementation, characterized by the angle φ, which includes the sound source and the main axis, as a central feature of the present invention.

III. example

The transfer of the subject invention to transducer systems leads to the following technical arrangement: Presented Schematic FIG. 3 or its computer simulation FIG. 5 provide an ideal pseudo-stereophonic signal based on the directional characteristics of a sphere, provided that the signals obtained are then of the prior art so-called stereo implementation described under "Equivalent Polar Pattern Combination Combinations of XY and MS Microphone Techniques" (US Pat. Diekreiter, 1987). The central characteristic here is the parameterization of the angle φ, the sound source and the main axis, which is technically exactly realized, clearly distinguishable from the arrangement.

IV. Derivation of a novel transducer system from III.

Based on the described application example, a forteriori a completely novel Schallwandle r system can be derived, such as in the form FIG. 7, which is the arbitrarily segmented uptake of sound events in a room de facto without restrictions or interference. The, binaural models exactly enabling function and construction principle is derived from FIG. 6 off.

V. Compatibility of the arrangement III. derived stereo signal

From a purely mathematical point of view, the stereo signal derived from the application example, III., Yields a completely compatible one, as long as the sound source does not come to rest on the main axis of the sound transducer.

In practice, this special case of resulting monophony remains easily correctable, and even has the desirable effect of being able to realize a purely monophonic reproduced sound source with a monomicrophone within a complete stereoscopic vision.

VI. Compatibility of the stereo signal (s) derived from device IV.

The effect described in V. can be used specifically in the derivative IV (which, incidentally, for the installation of so-called interface microphones (Wuttke, 2000 2000, probably after Müller, Black, Davies, Bell Telephone, 1937) in an arbitrarily segmented body, as shown in FIG. 7). If such an arrangement so-called room or support microphones (Dickreiter, 1987) according to the considerations FIG. 6 added, the result remains compatible.

The same applies to the special case of discontinuous segmentation, this corresponds to the classic case of the space or support microphone technology described by Dickreiter (Dickreiter, 1987).

For the disambiguation of compatibility, see Dickreiter (Dickreiter, 1987).

VII. Derivation of a technically realized binaural solution of IV. And VI.

The technical implementation according to IV. And VI. leads according to the considerations of FIG. 6 simultaneously for the reinforcement of the first main reflection mathematically and technically exactly defined in the normalized ear distance, which corresponds to an exactly realized complete binaural solution, and thus is able to satisfy complete stereophonic reproduction both in loudspeaker reproduction and in headphones.

VIII. Derivation of, the technical problem of common so-called stereo conversion (Dickreiter, 1987) generalized solving technical arrangements of III. to VII.

Compare this with "Equivalent directional characteristic combinations of the XY and MS microphone technique" in Dickreiter (Dickreiter, 1987), which illustrate the state of the art on the basis of examples.

In III. to VII., Part of the subject invention forming, technical arrangements are based on the postulated so-called opening angle 2α = 180 ^o .

However, it is under targeted parametrisierender extension of the circuit diagram FIG. 3 or its computational simulation FIG. 5 or related devices, which, this is a technical characteristic of the subject invention, the technically implemented targeted parameterization of the angle φ, the sound source and main axis include basically using the principles of action systematic so-called polarity reversal and Pegelum differences in transit times basically possible to achieve technical arrangements which are able to supply all the signal combinations corresponding to the technical state in the sense of Dickreiter's explanations (Dickreiter, 1987) or even expand this canon as desired!

Likewise, in such technical arrangements, part of the subject invention, a technical extension in accordance with the considerations IV., VI. and VII. 6 and FIG.7 realize, also this subject of the present invention.

The application to multi-channel systems results a forteriori, part of the subject invention.

IX. Practical technical conclusions from III. to VIII.

Overall, with the considerations III. to VIII. created on a completely new basis, part of the subject invention, throughout the current state of the art adequate canon of equipment and other technical equipment, the known repertoire of technical solutions in terms of. Sound systems change includes and even extended.

X. Stereophonic Telephony as Practical Application and Conclusion of III. to IX.

Without network expansion results from the in III. to IX. technical solutions shown the technical feasibility of pure stereophonic telephony on implementation of a corresponding mono signal according to the above considerations. This is part of the subject invention a forteriori.

XI. Transmission of III. to X. on any technical equipment

The transfer of III. to X. to any technical devices and modes of operation to which III. to X., is part of the subject invention.

XII. Practical application examples of transmissions according to XI. and conclusion

The application to Schallwandlerstysteme is exemplary of a basic technical problem that combines with the signal and data technology in general, and can be solved technically in the present form.

It should be explicitly stated that the application of the above-described technical solutions in this area leads to an automatic data reduction of at least 50 (!) Percent. The application of the subject invention allows completely new approaches, as a simple example in measurement and control technology. This process can be accelerated many times, if this subject of the invention is based. Further application examples are targeted technical applications that serve the data reduction in satellite technology and optoelectronics, and further technical systems that enable the multi-dimensional viewing of signal paths, such as shown here.

The invention also provides new technical solutions for highly efficient processor architectures.

In the sense of a conclusio, it remains fascinating that the subject of the invention refute theoretically as well as practically finally a theorem alleged since the work of Blumlein, namely the impossibility of exact stereophony on the basis of a mono signal (Dickreiter, 1987).

BRIEF DESCRIPTION OF THE FIGURES

• FIG. 1. Graphisch dargestelltes Funktionsprinzip der in Beschreibung dargestellten technischen Einrichtung einer sogenannt pseudostereophonen Umsetzung. (1) Ebene einer allfällig vorhandenen schallharten reflektierenden Grenzfläche. (2) Position des Schallwandlers mit kugelförmiger Richtcharakteristik. (3) Hauptachse des Schallwandlers, Position eines allfälligen Raum- oder Stützschallwandlers. (4) Position des technisch simulierten Schallwandlers mit kugelförmiger Richtcharakteristik, der mit (5) summiert das Seitensignal ergibt. (5) Position des technisch simulierten Schallwandlers mit kugelförmiger Richtcharakteristik, der mit (4) summiert das Seitensignal ergibt. (6) Der technisch realisierten Parametrisierung von ϕ entnommenes Maximum für (4). (7) Winkel ϕ, den Hauptachse und Schallquelle einschließen. (8) Der technisch realisierten Parametrisierung von ϕ entnommenes Maximum für (5). (9) Der technisch realisierten Parametrisierung von ϕ entnommene Phasendifferenz für (5). (10) Der technisch realisierten Parametrisierung von ϕ entnommene Phasendifferenz für (4). (11) Peilachse Schallquelle.
• FIG. 2. Graphische Darstellung der Signale gem. FIG. 1. (12) Zeitachse. (13) Pegelachse (14) Monosignal des Schallwandlers mit kugelförmiger Richtcharakteristik. (15) Der technisch realisierten Parametrisierung von ϕ entnommenes Maximum für (4). (16) Der technisch realisierten Parametrisierung von ϕ entnommene Phasendifferenz von (15). (17) Der technisch realisierten Parametrisierung von ϕ entnommenes Maximum des Eingangssignals. (18) Der technisch realisierten Parametrisierung von ϕ entnommene Phasendifferenz von (5). (19) Der technisch realisierten Parametrisierung von entnommenes Maximum für (5).
• FIG. 3. Signalverarbeitende, Teil des Erfindungsgegenstands bildende, Schaltung. Für L_A, L_B; P_M, P_B gelten die Beziehungen $${\mathrm{L}}_{\mathrm{A}}\mathrm{=}\sqrt{\frac{\mathrm{5}}{\mathrm{4}}\mathrm{-}\mathrm{sin\; y}}\mathrm{-}\frac{\mathrm{1}}{\mathrm{2}}$$
  
  $${\mathrm{L}}_{\mathrm{B}}\mathrm{=}\sqrt{\frac{\mathrm{5}}{\mathrm{4}}+\mathrm{sin\; y}}\mathrm{-}\frac{\mathrm{1}}{\mathrm{2}}$$
  
  sowie für maximalen Pegel P_max für den Pegel des Eingangssignals (resultierend aus kugelförmiger Richtcharakteristik) P_M bzw. die Pegel P_A, P_B der simulierten internen Signale (ebenfalls unter Beibehaltung kugelförmiger Richtcharakteristik) $${\mathrm{P}}_{\mathrm{A}}\mathrm{=}{\mathrm{P}}_{\max }\mathrm{,}{\mathrm{P}}_{\mathrm{M}}\mathrm{=}\frac{{\mathrm{P}}_{\max }}{\mathrm{(}\mathrm{1}\mathrm{-}\sqrt{\frac{\mathrm{5}}{\mathrm{4}}\mathrm{-}\mathrm{sin\; y}}{\mathrm{)}}^{\mathrm{2}}}$$
  
  $${\mathrm{P}}_{\mathrm{B}}\mathrm{=}{\mathrm{P}}_{\max }\mathrm{\cdot }\frac{\mathrm{(}\sqrt{\frac{\mathrm{5}}{\mathrm{4}}\mathrm{+}\mathrm{sin\; y}}{\mathrm{)}}^{\mathrm{2}}}{\mathrm{(}\mathrm{1}\mathrm{-}\sqrt{\frac{\mathrm{5}}{\mathrm{4}}\mathrm{-}\mathrm{sin\; y}}{\mathrm{)}}^{\mathrm{2}}}$$
  
  wobei ϕ≠ 0 (7) entspricht.
• FIG. 4. Darstellung korrelierender Parameter zu FIG.5. (20) Zeitachse, korrelierend mit den Werten t_i. (21) Pegelachse, korrelierend mit den Werten P_i(t_i). (22) Eingangssignal. (23) t_i. (24') P_i(t_i).
• FIG. 5. Flußdiagramm einer Rechensimulation von FIG. 3. M_i(t_i), S_i(t_i) entsprechen dabei dem Output i.S. errechneten Mono- bzw. Seitensignals.
• FIG. 6. Graphisch dargestelltes Funktionsprinzip der in Beschreibung dargestellten technischen Einrichtung, wie in VII. beispielhaft erläutert. (25) Schallquelle. (26) Ohrabstand (normiert
  
  = 0,175 m). (27) Position des Schallwandlers mit kugelförmiger Richtcharakteristik (Hauptsignal). (28) Position des Stützschallwandlers. (29) Tiefenausdehnung der Schallquelle. (30) Zentrische Streckung. (31) Phasendifferenz zwischen 1. und 2. Hauptreflexion.
• FIG. 7. Beispiel eines Schallwandlersystems, in seinem technischen Aufbau abgeleitet aus FIG. 3 und FIG. 5. (32) Kugelsphäre. (33) Schallharte reflektierende Grenzfläche. (34) Schallwandler. (35) Absorbierende Segmentflächen. (36) Distanzhalterung eines Stützschallwandlers, wobei sich für die Distanz von (34) und (37) exakt aus (30) und (31) zu bilden ist, maximal korrigiert um (29). Es ergibt sich für konkretes Beispiel eine Verstärkung des konkretes Beispiel eine Verstärkung der 1. Hauptreflexion exakt im Ohrabstand, Teil des Erfindungsgegenstands. (37) Stützschallwandler. (38) Aufhängung. Dieses Anwendungsbeispiel stellt ein mehrkanaliges System für die Anwendung in Konzert- und Opernhäuser dar. Ad (33) bis (36): Die Anzahl und Form der Segmente sind in dieser Anordnung beliebig bestimmbar!

The figures FIG.1 to FIG 7 are part of the subject invention and are included to illustrate further features of the subject invention. They are also for the understanding of III. to XII. indispensable and constitute specific examples of application of the invention presented.

• FIG. 1. Graphically represented functional principle of the technical device shown in the description of a so-called pseudostereophonic implementation. (1) plane of any reverberant reflective interface. (2) Position of the transducer with spherical directional characteristic. (3) Main axis of the sound transducer, position of any room or support sound transducer. (4) Position of the technically simulated transducer with spherical directional characteristic, which summed with (5) gives the side signal. (5) Position of the technically simulated transducer with spherical directional characteristic, which summed with (4) gives the side signal. (6) The technically realized parameterization of φ extracted maximum for (4). (7) Include angle φ, the major axis and sound source. (8) The technically realized parameterization of φ extracted maximum for (5). (9) The technically realized parameterization of φ extracted phase difference for (5). (10) The technically realized parameterization of φ extracted phase difference for (4). (11) Peilachse sound source.
• FIG. 2. Graphical representation of the signals acc. FIG. 1. (12) Timeline. (13) Level axis (14) Mono signal of the transducer with spherical directional characteristic. (15) The technically realized parameterization of φ extracted maximum for (4). (16) The technically realized parameterization of φ extracted phase difference of (15). (17) The technically realized parameterization of φ extracted maximum of the input signal. (18) The technically realized parameterization of φ extracted phase difference of (5). (19) The technically realized parameterization of extracted maximum for (5).
• FIG. 3. Signal processing, part of the subject invention forming, circuit. For L _A , L _B ; P _M , P _B are the relations $${\mathrm{L}}_{\mathrm{A}}\mathrm{=}\sqrt{\frac{\mathrm{5}}{\mathrm{4}}\mathrm{-}\mathrm{sin\; y}}\mathrm{-}\frac{\mathrm{1}}{\mathrm{2}}$$
  
  $${\mathrm{L}}_{\mathrm{B}}\mathrm{=}\sqrt{\frac{\mathrm{5}}{\mathrm{4}}+\mathrm{sin\; y}}\mathrm{-}\frac{\mathrm{1}}{\mathrm{2}}$$
  
  as well as for maximum level P _max for the level of the input signal (resulting from spherical directional characteristic) P _M or the levels P _A , P _{B of} the simulated internal signals (likewise while maintaining spherical directional characteristic) $${\mathrm{P}}_{\mathrm{A}}\mathrm{=}{\mathrm{P}}_{\mathrm{Max}}\mathrm{.}{\mathrm{P}}_{\mathrm{M}}\mathrm{=}\frac{{\mathrm{P}}_{\mathrm{Max}}}{\mathrm{(}\mathrm{1}\mathrm{-}\sqrt{\frac{\mathrm{5}}{\mathrm{4}}\mathrm{-}\mathrm{sin\; y}}{\mathrm{)}}^{\mathrm{2}}}$$
  
  $${\mathrm{P}}_{\mathrm{B}}\mathrm{=}{\mathrm{P}}_{\mathrm{Max}}\mathrm{\cdot }\frac{\mathrm{(}\sqrt{\frac{\mathrm{5}}{\mathrm{4}}\mathrm{+}\mathrm{sin\; y}}{\mathrm{)}}^{\mathrm{2}}}{\mathrm{(}\mathrm{1}\mathrm{-}\sqrt{\frac{\mathrm{5}}{\mathrm{4}}\mathrm{-}\mathrm{sin\; y}}{\mathrm{)}}^{\mathrm{2}}}$$
  
  where φ ≠ 0 (7).
• FIG. 4. Representation of correlating parameters to FIG. (20) Time axis, correlated with the values t _i . (21) Level axis, correlated with the values P _i (t _i ). (22) input signal. (23) t _i . (24 ') P _i (t _i ).
• FIG. 5. Flow chart of a computer simulation of FIG. 3. M _i (t _i ), S _i (t _i ) correspond to the output iS calculated mono or side signal.
• FIG. 6. Graphically illustrated operating principle of the technical device shown in the description, as exemplified in VII. (25) sound source. (26) Ear distance (normalized
  
  = 0.175 m). (27) Position of the transducer with spherical directional characteristic (main signal). (28) Position of the supporting sound transducer. (29) Depth of sound source. (30) Centric extension. (31) Phase difference between 1st and 2nd main reflection.
• FIG. 7. Example of a sound transducer system, derived in its technical construction of FIG. 3 and FIG. 5. (32) sphere sphere. (33) Sound-reflecting surface. (34) Sound transducer. (35) Absorbent Segment Surfaces. (36) Distance support of a support sound transducer, wherein for the distance of (34) and (37) to form exactly (30) and (31), corrected by (29). For a concrete example, an amplification of the concrete example results in an amplification of the first main reflection exactly in the ear distance, part of the subject of the invention. (37) Supersonic transducers. (38) Suspension. This application example represents a multichannel system for use in concert and opera houses. Ad (33) to (36): The number and Shape of the segments are arbitrarily determinable in this arrangement!

REFERENCES

• Michael Dickreiter: Handbuch der Tonstudiotechnik. Volume 1 - Munich etc .: Saur 1987 ,
• Kishii Tatsuya ea: complete letter JP 11146499 A , - Published 28.5.1999.
• Jörg Wuttke: Microphone attachments. 2nd edition - Karlsruhe: Schalltechnik Dr.-Ing. Schoeps GmbH 2000 ,

Claims (7)

All technical devices, arrangements and modes of action as well as their simulations, which are able to convert one or more monophonic sound signals into those which can be subordinated to common so-called stereo conversion, or technical devices arrangements and modes of action as well as their simulations, which have multi-channel, related property, in such a way that purely stereophonic or exclusively related to the multi-channel model output signals result, which are characterized by a technically or methodically realized parametrization of the angle φ, which includes sound source and main axis of the respective sound transducer unit. All technical devices, arrangements and modes of action and their simulations, which binaural or related, even multi-channel models directly on the ear or over radiation in space are able to realize technically, and are characterized by the technical or effective reinforcement of the 1st main reflection. All technical devices, arrangements and modes of action as well as their simulation, which are able to perceive or convert sound events, optionally characterized by any sectoral structure of the room, and in total by the application of technical devices, arrangements or modes of action or their simulation according to claims 1. and / or 2. All technical devices, arrangements and modes of action as well as their simulation, which are used for the transmission of sound events, images, data or other information or objects, these are characterized by the, possibly also in other areas transmitted application of technical facilities, arrangements and modes of action and their simulation according to other claims; In particular , this includes all technical devices, arrangements and modes of action and their simulation to understand which principles of action, as described in other claims, on sound in terms of stereophonic reproduction, image information in the sense of stereoscopic reproduction, or multi-channel equivalent or similar models, in particular Telephone networks, data networks. Audio lines, opto-electronic transmission equipment, radio links, interfaces, data lines and other terrestrial or other technical transmission equipment. All technical devices, arrangements and modes of action and their simulations, which, in terms of their object, their objects, their problem solving or their field of action is not necessarily determined, yet have characteristic features that correspond to technical devices, arrangements or modes of action or their simulations, as they correspond Derive from other claims. All technical devices, arrangements and modes of action and their simulations, which serve the purposeful reduction of accumulating information, objects or data or signals, and therein have one or more features, which in terms of their structure, their property or methodology as related or as a transmission or more targeted have to be considered reversal of features, and are characterized in that capacity as they refer to other claims. All technical devices, arrangements and modes of action as well as their simulations, which serve the targeted observation or measurement or representation, this in multi-dimensional form, of processes, processes or events of physical and other nature, and in terms of their structure, their property or methodology principles advantage make and are characterized , which equally use solutions according to other claims, in particular applications in the field of measurement and control technology.

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