Author: claimsbot

What is claimed is:

1. A compound having the following formula:
61
wherein:
(a) X is selected from the group consisting of
62
(b) R1 is selected from the group consisting of C3 to about C5 cycloalkyl, C1 to about C2 alkanyl, C2 to about C3 linear alkenyl, C3 to about C4 branched alkanyl or alkenyl, all such alkyl or cycloalkyl moieties being unsubstituted or substituted with from 1 to about 3 fluoro; and phenyl, unsubstituted or substituted with from 1 to about 3 fluoro, or with one hydroxy in the 4-position;
(c) R3 is hydrogen or hydroxy;
(d) R5 is selected from the group consisting of hydrogen, hydroxy, amino, halo, C1 to about C2 alkanyl, C2 alkenyl, and methoxy, all such alkyl and methoxy moieties being unsubstituted or substituted with from 1 to about 3 fluoro;
(e) R8 is selected from the group consisting of fluoro, chloro and bromo;
(f) R7 is amino which is attached to a ring carbon of X which is not adjacent to the ring nitrogen, the amino being unsubstituted or substituted with one or two C1 to about C3 alkanyl; or aminoalkanyl which is attached to any ring carbon of X and is C1 to about C3 alkanyl substituted with one amino, the amino being unsubstituted or substituted with one or two C1 to about C3 alkanyl;
(g) each R9 is independently selected from the group consisting of hydrogen, C1 to about C4 alkanyl, C2 to about C6 alkenyl or alkynyl, and a C3 to about C6 fused or spirocycle alkyl ring; or one R9 may optionally be selected from the group consisting of hydroxy, C1 to about C4 alkoxy, aryl and heteroaryl, all other R9 being hydrogen; all alkyl and aryl portions of R9 moieties being unsubstituted or substituted with one hydroxy or with from 1 to about 3 fluoro; and
(h) a R7 moiety described in (f) and a R9 moiety described in (g) may optionally be connected thus forming a fused or spirocycle ring with the N-containing ring shown in (a), the fused or spirocycle ring comprising from 2 to about 5 ring carbons and 0 or 1 ring nitrogen;
or an optical isomer, diastereomer or enantiomer thereof; a pharmaceutically-acceptable salt, hydrate, or biohydrolyzable ester, amide or imide thereof.
2. The compound of claim 1 wherein R3 is hydroxy, and X is
63
3. The compound of claim 2 wherein each R9 is independently selected from the group consisting of hydrogen, C1 to about C4 alkanyl, C2 to about C6 alkenyl or alkynyl, and a C3 to about C6 fused or spirocycle alkyl ring; all such alkyl moieties being unsubstituted or substituted with from 1 to about 3 fluoro.
4. The compound of claim 3 wherein:
(a) R1 is selected from the group consisting of C3 to C5 cycloalkanyl, methyl, ethyl, ethenyl, isopropyl, isopropenyl, isobutyl, isobutenyl, t-butyl, all such alkyl or cycloalkanyl moieties being unsubstituted or substituted with from 1 to 3 fluoro; and phenyl, unsubstituted or substituted with from 1 to 3 fluoro, or with one hydroxy in the 4-position;
(b) R5 is selected from the group consisting of hydrogen, hydroxy, amino, fluoro, chloro, bromo, and methyl, the methyl being unsubstituted or substituted with from 1 to 3 fluoro;
(c) R7 is attached to a ring carbon of X which is not adjacent to the ring nitrogen; and
(d) no more than two ring carbons of X have non-hydrogen R9’s attached thereto.
5. The compound of claim 4 wherein:
(a) R7 is amino which is attached to a ring carbon of X which is not adjacent to the ring N, the amino being unsubstituted or substituted with one or two C1 to about C3 alkanyl; or is C1 to about C3 alkanyl substituted with one amino;
(b) R9 is selected from the group consisting of hydrogen, C1 to about C4 alkanyl, C2 to about C6 alkenyl or alkynyl, and a C3 to about C6 spirocycle alkyl ring; all such alkyl moieties being unsubstituted or substituted with from 1 to about 3 fluoro.
6. The compound of claim 5 wherein R8 is chloro.
7. The compound of claim 4 wherein;
(a) R1 is selected from the group consisting of cyclopropyl, ethyl, phenyl substituted with 1 to 3 fluoro, and 4-hydroxyphenyl;
(b) R5 is selected from the group consisting of hydrogen, hydroxy, amino, and methyl;
(c) X comprises the piperidinyl ring;
(d) R7 is amino in the 3-position of the piperidinyl ring; and
(e) all R9 are hydrogen, or one non-hydrogen R9 is in the 4-position or 5-position of the piperidinyl ring.
8. The compound of claim 7 wherein:
(a) R1 is cyclopropyl;
(b) R5 is hydrogen, and
(c) all R9 are hydrogen, or one non-hydrogen R9 is selected from the group consisting of methyl, ethyl, dimethyl, spirocyclopropyl, methoxy, 2-thienyl and 2-furyl.
9. The compound of claim 8 wherein R8 is chloro.
10. The compound of claim 4 wherein:
(a) R1 is selected from the group consisting of cyclopropyl, ethyl, phenyl substituted with 1 to 3 fluoro, and 4-hydroxyphenyl;
(b) R5 is selected from the group consisting of hydrogen, hydroxy, chloro, bromo, amino, and methyl, the methyl being unsubstituted or substituted with from 1 to 3 fluoro;
(c) when X comprises the piperidinyl ring, R7 is amino unsubstituted or substituted with one C1 to C3 alkanyl or two methyl; when X comprises the pyrrolidinyl ring, R7 is aminoalkanyl which is methyl or ethyl or isopropyl substituted with one amino unsubstituted or substituted with one methyl or ethyl or dimethyl.
11. The compound of claim 10 wherein:
(a) R1 is cyclopropyl or ethyl, unsubstituted or substituted with from 1 to about 3 fluoro;
(b) R5 is selected from the group consisting of hydrogen, hydroxy, amino, and methyl;
(c) when X comprises the piperidinyl ring, R7 is amino or methylamino in the 3-position or 4-position of the ring; when X comprises the pyrrolidinyl ring, R7 is selected from the group consisting of aminomethyl, methylaminomethyl, 1-aminoethyl, 1-methylaminoethyl, 1-amino-1-methylethyl and 1-methylamino-1-methylethyl in the 3-position of the ring.
(d) all R9 are hydrogen or only one ring carbon of X has a non-hydrogen R9 attached thereto, such non-hydrogen R9 being selected from the group consisting of methyl, ethyl, dimethyl and spirocyclopropyl.
12. The compound of claim 11 wherein X comprises the pyrrolidinyl ring.
13. The compound of claim 12 wherein R1 is cyclopropyl, R5 is hydrogen, and all R9 are hydrogen.
14. The compound of claim 13 wherein R8 is chloro.
15. A compound selected from the group consisting of:
7-3R-(1S-aminoethylpyrrolidinyl)-1-ethyl-1,4-dihydro-8-chloro-6-hydroxy-4-oxo -3-quinolinecarboxylic acid;
7-3R-(1S-aminoethylpyrrolidinyl)-1-(2-fluoroethyl)-1,4-dihydro-8-chloro-6-hydroxy -4-oxo-3-quinolinecarboxylic acid;
7-3R-(1S-aminoethylpyrrolidinyl)-1-cyclopropyl-1,4-dihydro-8-chloro-6-hydroxy -4-oxo-3-quinolinecarboxylic acid;
7-3R-(1S-methylaminoethylpyrrolidinyl)-1-cyclopropyl-1,4-dihydro-8-chloro-6-hydroxy -4-oxo-3-quinolinecarboxylic acid;
7-3R-(1-amino-methylethylpyrrolidinyl)-1-cyclopropyl-1,4-dihydro-8-chloro-6-hydroxy -4-oxo-3-quinolinecarboxylic acid;
7-3R-(1-methylamino-methylethylpyrrolidinyl)1-cyclopropyl-1,4-dihydro-8-chloro -6-hydroxy-4-oxo-3-quinolinecarboxylic acid;
7-3R-(1S-aminoethyl-5-methyl-pyrrolidinyl)-1-cyclopropyl-1,4-dihydro-8-chloro -6-hydroxy-4-oxo-3-quinolinecarboxylic acid;
7-3R-(1S-aminoethyl-5,5-dimethyl-pyrrolidinyl)-1-cyclopropyl-1,4-dihydro-8-chloro -6-hydroxy-4-oxo-3-quinolinecarboxylic acid;
7-3R-(1-aminomethylethyl-5,5-dimethyl-pyrrolidinyl)-1-cyclopropyl-1,4-dihydro -8-chloro-6-hydroxy-4-oxo-3-quinolinecarboxylic acid;
7-3R-(1S-methylaminoethyl-5,5-dimethyl-pyrrolidinyl)-1-cyclopropyl-1,4-dihydro -8-chloro-6-hydroxy-4-oxo-3-quinolinecarboxylic acid;
7-3R-(1-methylaminomethylethyl-5,5-dimethyl-pyrrolidinyl)-1-cyclopropyl-1,4-dihydro -8-chloro-6-hydroxy-4-oxo-3-quinolinecarboxylic acid;
7-3R-(1S-aminoethyl-5-ethyl-pyrrolidinyl)-1-cyclopropyl-1,4-dihydro-8-chloro-6-hydroxy-4-oxo-3-quinolinecarboxylic acid;
7-3R-(1-aminomethylethyl-5-ethyl-pyrrolidinyl)-1-cyclopropyl-1,4-dihydro-8-chloro -6-hydroxy-4-oxo-3-quinolinecarboxylic acid;
7-3R-(1S-methylaminoethyl-5-ethyl-pyrrolidinyl)-1-cyclopropyl-1,4-dihydro-8-chloro -6-hydroxy-4-oxo-3-quinolinecarboxylic acid;
7-3R-(1-methylaminom ethylethyl-5-ethyl-pyrrolidinyl)1-cyclopropyl-1,4-dihydro -8-chloro-6-hydroxy-4-oxo-3-quinolinecarboxylic acid;
7-3R-(1-amino-1-cyclopropyl-methylpyrrolidinyl)-1-cyclopropyl-1,4-dihydro-8-chloro -6-hydroxy-4-oxo-3 -quinolinecarboxylic acid;
7-6R-(1S-aminoethyl)-4-azaspiro2.4heptanyl-1-cyclopropyl-1,4-dihydro-8-chloro -6-hydroxy-4-oxo-3-quinolinecarboxylic acid;
7-6R-(1S-methylaminoethyl)-4-azaspiro2.4heptanyl-1-cyclopropyl-1,4-dihydro -8-chloro-6-hydroxy-4-oxo-3-quinolinecarboxylic acid;
7-6R-(1S-amino-methylethyl)-4-azaspiro2.4heptanyl-1-cyclopropyl-1,4-dihydro -8-chloro-6-hydroxy-4-oxo-3-quinolinecarboxylic acid;
7-6R-(1S-methylamino-methylethyl)-4-azaspiro2.4heptanyl-1-cyclopropyl-1,4-dihydro -8-chloro-6-hydroxy-4-oxo-3-quinolinecarboxylic acid;
or a pharmaceutically-acceptable salt thereof.
16. A compound selected from the group consisting of:
7-3S-aminopiperidinyl-1-cyclopropyl-1,4-dihydro-8-chloro-6-hydroxy-4-oxo-3-quinolinecarboxylic acid;
7-3S-methylaminopiperidinyl-1-cyclopropyl-1,4-dihydro-8-chloro-6-hydroxy-4-oxo -3-quinolinecarboxylic acid;
7-3S-amino-4R-methyl-piperidinyl-1-cyclopropyl- 1,4-dihydro-8-chloro-6-hydroxy -4-oxo-3-quinolinecarboxylic acid;
7-3S-amino-5S-methyl-piperidinyl-1-cyclopropyl-1,4-dihydro-8-chloro-6-hydroxy -4-oxo-3-quinolinecarboxylic acid;
7-3S-amino-5R-methyl-piperidinyl-1-cyclopropyl-1,4-dihydro-8-chloro-6-hydroxy -4-oxo-3-quinolinecarboxylic acid;
7-3S-amino-4R-ethyl-piperidinyl-1-cyclopropyl-1,4-dihydro-8-chloro-6-hydroxy -4-oxo-3-quinolinecarboxylic acid;
7-3S-amino-6,6-dimethyl-piperidinyl-1-cyclopropyl-1,4-dihydro-8-chloro-6-hydroxy -4-oxo-3-quinolinecarboxylic acid;
7-3S-amino-6-methyl-piperidinyl-1-cyclopropyl-1,4-dihydro-8-chloro-6-hydroxy -4-oxo-3-quinolinecarboxylic acid;
7-7-amino-5-azaspiro2.5-octanyl1-cyclopropyl-1,4-dihydro-8-chloro-6-hydroxy -4-oxo-3-quinolinecarboxylic acid;
7-4-amino-6-azaspiro2.5-octanyl-1-cyclopropyl- 1,4-dihydro-8-chloro-6-hydroxy -4-oxo-3-quinolinecarboxylic acid;
or a pharmaceutically-acceptable salt thereof.
17. A pharmaceutical composition comprising:
(a) a safe and effective amount of a compound of claim 1 or 14; and
(b) a pharmaceutically-acceptable excipient.
18. A method for preventing or treating microbial infection comprising administering to a host in need of such a treatment a safe and antimicrobially effective amount of a compound of claim 1 or 14.

The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.

1. An angular ball bearing comprising:
an outer ring having an inner peripheral surface, an outer peripheral surface, and a radially inwardly-facing outer raceway groove formed in said inner peripheral surface of said outer ring;
an inner ring disposed within said outer ring and having an inner peripheral surface, an outer peripheral surface, and a radially outwardly-facing inner raceway groove formed in said outer peripheral surface of said inner ring; and
a plurality of rolling elements disposed in said inner raceway groove and said outer raceway groove and radially between said inner ring and said outer ring;
wherein said inner peripheral surface of said outer ring includes a first annular inner peripheral surface portion on a first axial side of said outer raceway groove, and a second annular inner peripheral surface portion on a second axial side of said outer raceway groove;
wherein said outer peripheral surface of said inner ring includes a first annular outer peripheral surface portion on a first axial side of said inner raceway groove, and a second annular outer peripheral surface portion on a second axial side of said inner raceway groove;
wherein said first annular inner peripheral surface portion of said inner peripheral surface of said outer ring is disposed to face said first annular outer peripheral surface portion of said outer peripheral surface of said inner ring across a first annular radial gap that has an annular opening that opens axially outwardly on said first axial side of said inner and outer raceway grooves;
wherein said second annular inner peripheral surface portion of said inner peripheral surface of said outer ring is disposed to face said second annular outer peripheral surface portion of said outer peripheral surface of said inner ring across a second annular radial gap that has an annular opening that opens axially outwardly on said second axial side of said inner and outer raceway grooves;
wherein an inner diameter of said first annular inner peripheral surface portion of said inner peripheral surface of said outer ring is greater than an inner diameter of said second annular inner peripheral surface portion of said inner peripheral surface of said outer ring;
wherein an outer diameter of said first annular outer peripheral surface portion of said outer peripheral surface of said inner ring is greater than an outer diameter of said second annular outer peripheral surface portion of said outer peripheral surface of said inner ring;
wherein a first annular seal is press fit into one of said first and second radial gaps so as to be press fit between one of (a) said first annular inner peripheral surface portion of said inner peripheral surface of said outer ring and said first annular outer peripheral surface portion of said outer peripheral surface of said inner ring, and (b) said second annular inner peripheral surface portion of said inner peripheral surface of said outer ring and said second annular outer peripheral surface portion of said outer peripheral surface of said inner ring;
wherein said inner peripheral surface of said outer ring has no inner peripheral surface portion that both protrudes radially inwardly further than an inner peripheral contact surface portion at which said first annular seal contacts said inner peripheral surface of said outer ring, and is disposed closer than said inner peripheral contact surface portion to the annular opening of said one of said first and second radial gaps in which said first annular seal is press fit;
wherein said outer peripheral surface of said inner ring has no outer peripheral surface portion that both protrudes radially outwardly further than an outer peripheral contact surface portion at which said first annular seal contacts said outer peripheral surface of said inner ring, and is disposed closer than said outer peripheral contact surface portion to the annular opening of said one of said first and second radial gaps in which said first annular seal is press fit;
wherein a portion of said inner peripheral surface of said outer ring extending between said inner peripheral contact surface portion and said radially inwardly-facing outer raceway groove constitutes a conical surface; and
wherein said inner diameter of said first annular inner peripheral surface portion of said inner peripheral surface of said outer ring is substantially uniform over the entire axial length of said first annular inner peripheral surface portion.

1. A tire inflation pressure determining apparatus, comprising:
an antenna for converting variations in a supplied electromagnetic field applied from the exterior, and generating electromagnetic field fluctuations toward the exterior;
an inflation pressure sensor whose electric capacitance varies in accordance with air pressure inside a tire;
a sensor resonance circuit for producing electrical resonance in accordance with the electric capacitance;
a data generation circuit for generating transmission data that includes information of the air pressure on the basis of intensity of the electrical resonance; and
a response circuit for varying electric current that flows to the antenna in accordance with bit values of the transmission data represented by digital data, and generating the electromagnetic field fluctuations, wherein
the transmission data is transmitted to the exterior with the aid of the electromagnetic field fluctuations.
2. The tire inflation pressure determining apparatus of claim 1, wherein:
a clock generation circuit for generating a clock having a frequency that corresponds to the receiving frequency on the basis of the AC signals having a predefined receiving frequency outputted from the antenna, and
an excitation coil to which the clock is inputted, wherein
the sensor resonance circuit has a resonance coil that constitutes an LC resonance circuit together with the electric capacitance and is electromagnetically coupled to the excitation coil.
3. The tire inflation pressure determining apparatus of claim 2, wherein the antenna has a coil and a capacitor that constitute a parallel LC resonance circuit for resonating at the receiving frequency.
4. The tire inflation pressure determining apparatus of claim 1, wherein:
the apparatus is used under conditions that the supplied electromagnetic field varies at a supply frequency that is selectively switched between a first frequency and a second frequency in a time sharing fashion;
the antenna resonates at the first transmission frequency and increases the output of the drive power; and
the sensor resonance circuit has a resonance coil that constitutes an LC resonance circuit together with the electric capacitance and that is excited by the transmission electromagnetic field, and has a resonance frequency that corresponds to the second transmission frequency.
5. The tire inflation pressure determining apparatus of claim 4, wherein the antenna has a coil and a capacitor that constitute a parallel LC resonance circuit for resonating at the first frequency.
6. The tire inflation pressure determining apparatus of claim 1, wherein the response circuit is a switching circuit for switching impedance of the antenna in accordance with the bit value.
7. The tire inflation pressure determining apparatus of claim 1, wherein a power circuit for rectifying and accumulating AC drive power generated in the antenna.
8. The tire inflation pressure determining apparatus of claim 1, wherein a temperature sensor for determining temperature inside a tire, wherein the data generation circuit includes information about the temperature in the transmission data.
9. The tire inflation pressure determining apparatus of claim 1, wherein a memory in which associated information related to the tire on which the sensor unit is mounted is stored in advance, wherein the data generation circuit includes the associated information in the transmission data.
10. The tire inflation pressure determining apparatus of claim 1, wherein:
a level-sensing circuit for sensing a strong connection state in which amplitude of an AC signal outputted from the antenna in accordance with the variations in the transmission electromagnetic field is at a predefined level or higher; and
a response circuit for varying electric current that flows to the antenna in accordance with bit values of the transmission data represented by digital data, and generating the electromagnetic field fluctuations when the strong connection state has been sensed.
11. The tire inflation pressure determining apparatus of claim 10, wherein:
the data generation circuit generates the transmission data, which includes information of the strong connection state in addition to information of the air pressure; and
the rotational speed of a tire can be measured by allowing information of the strong connection state included in the transmission data to be periodically received in the exterior.
12. The tire inflation pressure determining apparatus of claim 10, wherein the antenna has a coil and a capacitor that constitute a parallel LC resonance circuit for resonating at a fluctuation frequency of the supplied electromagnetic field.
13. The tire inflation pressure determining apparatus of claim 10, wherein:
a clock generation circuit for generating, based the AC signal, a clock having a frequency that corresponds to a fluctuation frequency of the supplied electromagnetic field, and an excitation coil to which the clock is inputted; and wherein
the sensor resonance circuit has a resonance coil that constitutes an LC resonance circuit together with the electric capacitance and is electromagnetically coupled to the excitation coil.
14. A tire inflation pressure determining apparatus, comprising:
an antenna for converting variations in a supplied electromagnetic field applied from the exterior, and generating electromagnetic field fluctuations toward the exterior;
a level-sensing circuit for sensing a strong connection state in which amplitude of an AC signal outputted from the antenna in accordance with the variations in the supplied electromagnetic field is at a predefined level or higher;
an inflation pressure sensor for determining air pressure inside a tire;
a data generation circuit for generating transmission data that includes information of the air pressure; and
a response circuit for varying electric current that flows to the antenna in accordance with bit values of the transmission data represented by digital data, and generating the electromagnetic field fluctuations when the strong connection state has been sensed, wherein the transmission data is transmitted to the exterior with the aid of the electromagnetic field fluctuations.
15. The tire inflation pressure determining apparatus of claim 14, wherein the antenna has a coil and a capacitor that constitute a parallel LC resonance circuit for resonating at a fluctuation frequency of the supplied electromagnetic field.
16. The tire inflation pressure determining apparatus of claim 14, wherein:
the inflation pressure sensor has an electric capacitance that varies in accordance with the air pressure;
the tire inflation pressure determining apparatus furthermore has a sensor resonance circuit for generating electrical resonance in accordance with the electric capacitance; and
the data generation circuit generates transmission data that includes information of the air pressure on the basis of intensity of the electrical resonance.
17. The tire inflation pressure determining apparatus of claim 16, wherein:
a clock generation circuit for generating a clock having a frequency that corresponds to a fluctuation frequency of the supplied electromagnetic field on the basis of the AC signal, and an excitation coil to which the clock is inputted; and
the sensor resonance circuit has a resonance coil that constitutes an LC resonance circuit together with the electric capacitance and is electromagnetically coupled to the excitation coil.
18. The tire inflation pressure determining apparatus of claim 14, wherein the response circuit is a switching circuit for switching impedance of the antenna in accordance with the bit value.
19. The tire inflation pressure determining apparatus of claim 14, wherein a power circuit for rectifying and accumulating AC drive power generated in the antenna.
20. A tire inflation pressure determining apparatus, comprising:
an antenna for converting variations in a supplied electromagnetic field applied from the exterior, and generating electromagnetic field fluctuations toward the exterior,
a level-sensing circuit for sensing a strong connection state in which amplitude of an AC signal outputted from the antenna in accordance with the variations in the supplied electromagnetic field is at a predefined level or higher;
an inflation pressure sensor for determining air pressure inside a tire;
a data generation circuit for generating transmission data that includes information of the air pressure and information of the strong connection state; and
a response circuit for varying electric current that flows to the antenna in accordance with bit values of the transmission data represented by digital data, and generating the electromagnetic field fluctuations when the strong connection state has been sensed; and wherein
the transmission data is transmitted to the exterior with the aid of the electromagnetic field fluctuations, and the rotational speed of a tire can be measured by allowing information of the strong connection state to be periodically received at the exterior.

The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.

What is claimed is:

1. An apparatus for producing spatially distributed sound into a set of headphones having left and right ear-cups, said apparatus comprising:
an input for receiving a sound signal including a left channel signal, a right channel signal, and a front channel signal;
dividing means for dividing the front channel signal into two secondary front channel signals;
left output means for outputting the left channel signal and one of the secondary front channel signals into the left ear-cup; and
right output means for outputting the right channel signal and another one of the secondary front channel signals into the right ear-cup.
2. An apparatus according to claim 1, wherein:
the left output means include a first and a second left transducer for respectively outputting the left channel signal and the one of the secondary front channel signals; and
the right output means include a first and a second right transducer for respectively outputting the right channel signal and the other one of the secondary front channel signals.
3. An apparatus according to claim 2, wherein:
the left output means include a third left transducer for outputting a copy of the right channel signal; and
the right output means include a third right transducer for outputting a copy of the left channel signal.
4. An apparatus according to claim 1, wherein the sound signal includes a rear channel signal, the dividing means being adapted to divide said rear channel signal into two secondary rear channel signals, the left output means being adapted to output one of said secondary rear channel signals into the left ear-cup, and the right output means being adapted to output another one of said secondary rear channel signals into the right ear-cup.
5. An apparatus according to claim 4, wherein:
the left output means include a first, second and third left transducer for respectively outputting the left channel signals and each one of the secondary front and rear channel signals; and
the right output means include a first, second and third right transducer for respectively outputting the right channel signal and each of the other ones of the secondary front and rear channel signals.
6. An apparatus according to claim 4, further comprising a stereophonic to surround sound decoding circuit for receiving a stereophonic signal and decoding said stereophonic signal to produce the sound signal supplied into the input.
7. An apparatus according to claim 6, wherein said stereophonic to surround sound decoding circuit comprises a 3D processor.
8. An apparatus according to claim 4, further comprising phase adjusting means for adjusting the phase of each of the front and rear channel signals.
9. An apparatus according to claim 4, wherein the left and right output means each include an acoustic delay line for introducing a delay of an order of a millisecond to the secondary rear channel signal with respect to the secondary front channel signal.
10. A set of headphones, comprising a left ear-cup, a right ear-cup and an apparatus according to claim 4.
11. A set of headphones according to claim 10, wherein the first left and right transducers are disposed towards a front portion of a corresponding one of the left and right ear-cups, the second left and right transducers being disposed in a central portion of said corresponding ear-cup, and the third left and right transducers being disposed towards a rear portion of said corresponding ear-cup.
12. A method for producing spatially distributed sound into a set of headphones having left and right ear-cups, said method comprising the steps of:
a) receiving a sound signal including a left channel signal, a right channel signal, and a front channel signal;
b) dividing the front channel signal into two secondary front channel signals;
c) outputting the left channel signal and one of the secondary front channel signals into the left ear-cup; and
d) outputting the right channel signal and another one of the secondary front channel signals into the right ear-cup.
13. A method according to claim 12, wherein the sound signal received in step a) includes a rear channel signal, and said method further comprises:
in step b), dividing said rear channel signal into two secondary rear channel signals,
in step c), outputting one of said secondary rear channel signals into the left ear-cup; and
in step d), outputting another one of said secondary rear channel signals into the right ear-cup.