FIELD OF THE INVENTION
This application claims priority under 35 U.S.C. 119(e) from U.S. Provisional Application Ser. No 60/614,521 filed 30 Sep. 2004, which application is incorporated herein by reference.
- LIMITED COPYRIGHT WAIVER
The invention relates generally to wagering gaming systems, and more specifically to a wagering game machine employing crosstalk cancellation.
- BACKGROUND OF THE INVENTION
A portion of the disclosure of this patent document contains material to which the claim of copyright protection is made. The copyright owner has no objection to the facsimile reproduction by any person of the patent document or the patent disclosure, as it appears in the U.S. Patent and Trademark Office file or records, but reserves all other rights whatsoever.
A wide variety of gaming devices are now available to gamers and to casino operators in computerized form, from slot machines to games that are traditionally played live such as poker and blackjack. These computerized games provide many benefits to the game owner and to the gambler, including greater reliability than can be achieved with a mechanical game or human dealer, more variety, sound, and animation in presentation of a game, and a lower overall cost of production and management.
Computerized video game systems must be designed with many of the same concerns as their mechanical and table game ancestors—they must be fair, they must provide sufficient feedback to the gamer to make the game fun to play, and they must meet a variety of gaming regulations to ensure that both the machine owner and gamer are honest and fairly treated in implementing the game. Further, they must provide a gaming experience that is at least as attractive as the older mechanical gaming machine experience to the gamer, to ensure success in a competitive gaming market.
Many computerized wagering game systems have a variety of sound and graphical elements designed to attract and keep a game player's attention, such as sound effects, music, and animation. These game presentation features often include a variety of music, sound effects, and voices presented to complement a video presentation of the wagering game on a display.
Wagering game players typically stand or sit on one side of a wagering game, and interact with the game such as by pushing buttons, pulling levers, and operating a touchscreen. The wagering game system in turn provides feedback to the game player via the display and one or more speakers. Use of multiple speakers in some wagering games allow playback of stereo audio in which each of the two stereo audio channels plays a different signal. Because the speakers are in different physical locations and are playing different audio signals, the sound presented to the game player through the speakers presents a soundstage in which instruments, voices, and other sounds can sound as though they come from different points between the speakers, creating the illusion of a broad or spacious array of instruments or other audio sources.
But, because the speakers are typically not very far apart, and because audio from each speaker is typically easily heard by both ears, the separation in a stereo speaker system such as that often employed in wagering game machines lacks the stereo channel separation that is heard for example when using headphones, in which each driver is heard by only one ear.
- SUMMARY OF THE INVENTION
It is therefore desired to achieve greater stereo separation in a wagering game machine.
BRIEF DESCRIPTION OF THE FIGURES
The present invention provides in one embodiment a computerized wagering game system has a gaming module comprising a processor and gaming code which is operable when executed on the processor to conduct a wagering game on which monetary value can be wagered. An audio module comprising a part of the computerized wagering game system is operable to play audio through two or more speakers, and is further operable to apply crosstalk cancellation to the audio played through the two or more speakers. A
FIG. 1 shows a computerized reel slot gaming system having audio crosstalk cancellation, consistent with an embodiment of the present invention.
FIG. 2 is a top view of a computerized reel slot gaming system having audio crosstalk cancellation and a wagering game player, consistent with an embodiment of the present invention.
FIG. 3 is a diagram of a crosstalk cancellation system as may be used to practice various embodiments of the present invention.
FIG. 4 is a frequency response graph shows head response characteristics as are used to derive a crosstalk cancellation filter in various embodiments of the present invention.
FIG. 5 is a diagram of a wagering game system employing attached seating, consistent with an example embodiment of the invention.
In the following detailed description of sample embodiments of the invention, reference is made to the accompanying drawings which form a part hereof, and in which is shown by way of illustration specific sample embodiments in which the invention may be practiced. These embodiments are described in sufficient detail to enable those skilled in the art to practice the invention, and it is to be understood that other embodiments may be utilized and that logical, mechanical, electrical, and other changes may be made without departing from the spirit or scope of the present invention. The following detailed description is, therefore, not to be taken in a limiting sense, and the scope of the invention is defined only by the appended claims.
The present invention provides in one embodiment a computerized wagering game system having a gaming module comprising a processor and gaming code which is operable when executed on the processor to conduct a wagering game on which monetary value can be wagered, and an audio module comprising a part of the computerized wagering game system that is operable to play audio through two or more speakers and to apply crosstalk cancellation to the audio played through the two or more speakers. An example of such a wagering game system is shown and described in FIG. 1.
FIG. 1 illustrates a computerized wagering game machine system, as may be used to practice various embodiments of the present invention. The computerized gaming system shown generally at 100 is a video wagering game system, which displays information for at least one wagering game upon which monetary value can be wagered on touchscreen video display 101. The touchscreen video display 101 is in various embodiments a CRT display, a plasma display, an LCD display, a field emission display, or any other type of display suitable for displaying electronically provided display information. Further embodiments include alternate or additional displays which may or may not be touchscreen displays, such as a second display located above the primary display, or other displays coupled to the wagering game system. Alternate embodiments of the invention will include other game indicators, such as mechanical reels instead of or in addition to the video graphics reels shown at 102 that comprise a part of a video slot machine wagering game.
A game of chance is implemented using software within the wagering game, such as through instructions stored on a machine-readable medium such as a hard disk drive or nonvolatile memory. In some further example embodiments, some or all of the software stored in the wagering game machine is encrypted or is verified using a hash algorithm or encryption algorithm to ensure its authenticity and to verify that it has not been altered. For example, in one embodiment the wagering game software is loaded from nonvolatile memory in a compact flash card, and a hash value is calculated or a digital signature is derived to confirm that the data stored on the compact flash card has not been altered. The game of chance implemented via the loaded software takes various forms in different wagering game machines, including such well-known wagering games as reel slots, video poker, blackjack, craps, roulette, or hold 'em games. The wagering game is played and controlled with inputs such as various buttons 103 or via the touchscreen video display 101. In some alternate examples, other devices such as pull arm 104 used to initiate reel spin in this reel slot machine example are employed to provide other input interfaces to the game player.
Monetary value is typically wagered on the outcome of the games, such as with tokens, coins, bills, or cards that hold monetary value. The wagered value is conveyed to the machine through a changer 105 or a secure user identification module interface 106, and winnings are returned via the returned value card or through the coin tray 107. Sound is also provided through speakers 108, typically including audio indicators of game play, such as reel spins, credit bang-ups, and environmental or other sound effects or music to provide entertainment consistent with a theme of the computerized wagering game. In some further embodiments, the wagering game machine is coupled to a network, and is operable to use its network connection to receive wagering game data, track players and monetary value associated with a player, and to perform other such functions.
FIG. 2 shows a diagram of a wagering game system employing two speakers and crosstalk cancellation, and a game player. A wagering game system such as that of FIG. 1 is shown in top view at 201, such as a video slot machine, a video poker machine, or other such wagering game. The wagering game system has two speakers 202 and 203 located on either side of the machine, which in this example embodiment are located at the same height but spaced beside one another. In alternate embodiments more speakers are present, such as including a center channel speaker located between speakers 202 and 203, or including speakers located above or below a horizontal plane. The speakers each convert an electrical audio signal to an audible acoustic signal that the game player 204 can hear. In a variety of embodiments, speakers 202 and 203 are fed separate audio signals, creating a stereo or surround effect for the game player in which the reproduced audible signal or portions of the audible signal produced by the speakers appear to come from different locations. But, the sound produced by left speaker 202 can be heard in both the left ear 205 of the game player and the right ear 206 of the game player. This is an example of crosstalk, in which sound intended for one ear is heard by the other ear, as shown in FIG. 2. Such crosstalk limits the ability of the speakers to present sounds that sound to the game player as though they come from different positions, such as outside the area between the two speakers 202 and 203.
The present invention in one example embodiment seeks to remedy this crosstalk effect by employing crosstalk cancellation, designed to limit the amount of sound intended for one of a game player's ears that is heard by the other ear. This is achieved such as by the filter processing method illustrated in FIG. 3, which shows one way of constructing and applying a crosstalk cancellation filter.
The left channel electrical signal 301 and the right channel electrical signal 302 are each fed to a crosstalk canceller 303 and 304, which in many embodiments are derived from the known impulse or frequency responses of a given ear's ability to hear sound from a speaker producing a signal intended for that ear (s), and a known impulse or frequency response of the game player's opposite ear not intended to hear the speaker's sound (a). The signal paths (s) and (a) are shown in FIG. 3 at 305 and 306, and the impulse or frequency response can be determined, for example, by use of an artificial head and ear apparatus and appropriate microphones.
In one example, the crosstalk cancellers 303 and 304 use the Z-transform function C(z)=−A(z)/S(z), and provide the output C(z) to the summers 307 and 308. The summers add the signals from the left channel source 301 and the right channel source 302 to the signals produced by the respective crosstalk cancellation circuits 304 and 303, which provide their additive output to equalizers 309 and 310. The equalizers are designed in some examples to ensure that the spectral content of the signal provided to the left or right speaker closely matches the spectral content of the respective input signal 301 or 302. The z-transform formula often used for equalization in crosstalk systems such as that of FIG. 3 is E(z)=(1/S(z))(1/(1-cˆ2(z))), but such equalization can be performed by a variety of other ways, such as by using a digital filter to provide equalized response derived from measurements taken of a particular constructed crosstalk cancellation network.
Many methods of crosstalk cancellation such as the filter of FIG. 3 and some digital filtering techniques work because the frequency response or the impulse response of a game player's left and right ears hearing the same single source is different. The difference between the left and right ear response is based on the position of the sound source relative to the listener's head, which allows come embodiments of the invention to use the varying response characteristics of the listener's ears to apply filtering to simulate the response characteristics so that sounds heard by the game player appear to come from specific locations.
FIG. 4 illustrates one example of frequency response curves characteristic of a game player's frequency response to a speaker offset to one side of the player's head, as shown in FIGS. 2 and 3. The desired ear's response curve (a) when compared with the undesired crosstalk ear's response (a) can help in understanding how the head hears sounds from various directions, and how this can be applied to crosstalk cancellation technology.
The functions appear to have nearly the same frequency response at low frequencies, making crosstalk cancellation at low frequencies a difficult task. At higher frequencies, the curves diverge, and a boost of about 30 dB occurs centered around a frequency of about 3 kHz. The auditory canal resonances and concha resonance within the game player's ear combine to create this increase in response, and contribute to the dips and peaks at higher frequencies along with physical characteristics of the pinna. These differences show how parameters for a crosstalk cancellation module such as that of FIG. 3 can be determined for various configurations of computerized wagering game machines. The example method described here assumes a typical head in a typical location for wagering game play, such as a wagering game player sitting on a stool or in a chair having a known average head position. Just as with normal stereo recordings, the effect of crosstalk cancellation is best heard when the wagering game player's head is in a predicted “sweet spot”, or within a certain range of physical locations. While the wavelength of audio signals can be many feet at low frequencies, it is reduced to inches at higher audible frequencies. Fortunately, the wagering game player's head acts as a more effective baffle or sound blocker at high frequencies, and reduces the need for sweet spot location for effective crosstalk cancellation. Nevertheless, further embodiments of the wagering game systems will employ built-in seating to ensure that a game player's head position is within a desired range, or will be able to estimate a game player's head position such as by optical, sonic, or other wagering game player detection methods.
One such example is shown in FIG. 5, which illustrates use of an audio game chair to position the game player's head, and to provide rear or surround speakers. The wagering game cabinet 501 is similar to the wagering game cabinet shown generally in FIG. 1, but here is placed on a stand 502. The stand couples the wagering game system 501 to a chair 503, containing in some further embodiments one or more speakers 504. The chair serves to position the head of the wagering game player in a desired location during game play or at other times when the game player is seated in the chair and facing the wagering game machine cabinet 501, making audio effects such as crosstalk cancellation filtering more effective. Further, addition of speakers mounted in or on the audio chair enhances the wagering game system's ability to present sounds as though they come from different locations, and enables use of surround sound technologies to supplement or enhance crosstalk cancellation.
The examples shown herein have illustrated how crosstalk cancellation can be employed in a wagering game system to enhance the ability of a speaker in a sound system having two or more speakers to provide sound to a wagering game player with reduced crosstalk. Although specific embodiments have been illustrated and described herein, it will be appreciated by those of ordinary skill in the art that any arrangement which is calculated to achieve the same purpose may be substituted for the specific embodiments shown. This application is intended to cover any adaptations or variations of the invention. It is intended that this invention be limited only by the claims, and the full scope of equivalents thereof.