CROSS REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application is a divisional of its parent U.S. application Ser. No. 11/595,031 having a filing date of Nov. 9, 2006 which is hereby incorporated herein in its entirety by reference. This application claims the benefit of priority of the filing date of its above referenced parent application. 
     
    
     FIELD OF INVENTION 
       [0002]    The field of the various embodiments of this invention relates to ambient condition detectors and systems and methods of operating ambient condition detectors and systems having an audible alarm with a selectable tone pitch. 
       BACKGROUND 
       [0003]    The pitch of tones within tonal patterns emitted by ambient condition detector units and systems in the alarm or testing state is not always optimum to be heard by a wide range of users. As one example, the elderly often suffer from a deficit of high frequency hearing sensitivity and may hear a lower pitch tonal pattern better than a higher pitch pattern. Other users may respond better to a higher pitch tonal pattern. As another example, various types of ambient noise may result in a tonal pattern containing preferred pitch tones that could most readily be heard in the event of a sensed ambient condition. Many conventional ambient condition detectors emit a tonal pattern with an average tone pitch on the order of 3 kHz in frequency. 
     
    
     
       BRIEF DESCRIPTIONS OF THE DRAWINGS 
         [0004]      FIG. 1  is a block diagram of one embodiment of the invention using control electronics with audio pitch control capability to control the pitch of the tones emitted by the audio output transducer. 
           [0005]      FIG. 2  is a block diagram of one embodiment of the invention using an audio output pitch selector to control the pitch of the tones emitted by the audio output transducer. 
           [0006]      FIG. 3  is an example tonal pattern illustrating an inter-group alternating pitch sequence in one embodiment. 
           [0007]      FIG. 4  is an example tonal pattern illustrating a ramped intra-group pitch sequence in one embodiment. 
           [0008]      FIG. 5  is an example tonal pattern illustrating an alternating intra-group pitch sequence in one embodiment. 
           [0009]      FIG. 6  is an example tonal pattern illustrating an inter-group alternating pitch sequence typically used in one gas detector embodiment. 
           [0010]      FIG. 7  is a flow chart of an electronic instruction set to permit the user to select a pitch of at least one tone to be output when an ambient condition is detected. 
           [0011]      FIG. 8  is a flow chart of an electronic instruction set to permit the user to select a tonal pattern comprising at least two distinctly different pitch tones when an ambient condition is detected. 
           [0012]      FIG. 9  illustrates one example of the flow diagram for a user-selected tone pitch for one embodiment with low, medium, and high pitches (high pitch selection indicated by the solid arrow in this example). 
       
    
    
     DETAILED DESCRIPTION 
       [0013]    While the various embodiments of this invention can take many different forms, specific embodiments thereof are shown in the drawings and will be described in detail herein with the understanding that the present disclosure is to be considered as an exemplification of the principles of the invention and is not intended to limit the scope of the invention to any specific embodiments illustrated or described. 
         [0014]    One of the embodiments is an ambient condition detector unit shown in  FIG. 1  where an ambient condition sensor  10  is connected to control electronics with audio pitch control  20  such that sensing of an ambient condition by ambient condition sensor  10  provides an input signal to the control electronics with audio pitch control  20 . The control electronics with audio pitch control  20  may be microprocessor based in one embodiment, and may be ASIC based in another embodiment and may contain electronic memory for one or more alarm tonal patterns comprising one or more pitch tones included within the tonal patterns and one or more silent periods within the tonal patterns. When the ambient condition sensor  10  senses an ambient condition, the control electronics with audio pitch control  20  sends an output signal to the audio output transducer  30  such that the audio output transducer  30  emits a tonal pattern comprising tones having pitch controlled by the control electronics with audio pitch control  20 . The control electronics with audio pitch control  20  controls the tonal pattern and tonal pitch. 
         [0015]    In at least one embodiment, a tone group comprises tones separated by at least one silent period. The silent period between repeating of the tone group is longer than the silent periods within the tone group. For example, in  FIG. 3 ,  FIG. 4 , and  FIG. 5  the first three tones illustrated comprise a first tone group and the second three tones illustrated in each figure comprise a second tone group separated from the first tone group by at least twice the time present between any two tones within a tone group. Times between tone groups are called inter-group temporal spacing  210 ,  310 , and  410  and times between individual tones within a tone group are call intra-group temporal spacing  200 ,  300 , and  400 . It is noted that the illustrative example of three tones in a tone group as shown in  FIG. 3 ,  FIG. 4 , and  FIG. 5  are not intended to be limiting. More or less than three tones may comprise a tone group, in general, as is shown in an example in  FIG. 6 . 
         [0016]    In one embodiment, the tonal pattern comprises tone groups with intra-group temporal spacing of a first amount and inter-group temporal spacing of a second amount wherein the second amount is at least twice as much as the first amount wherein the tones comprise at least two distinctly different pitches. 
         [0017]    Distinctly different pitches means that a normal human ear can detect a difference between the pitches (often referred to a just noticeable difference). As one example, the just noticeable difference in pitch for the normal human ear is on the order of 0.5% of the tone frequency when that tone frequency is on the order of a few thousand hertz. Other values of just noticeable differences in pitch for the normal human ear are well known in the field of acoustics. It is noted that tone pitches may be composites of more than one tone frequency and still fall within the scope of the invention. As such, distinctly different pitches may also be composites of more than one tone frequency so long as a normal human ear can detect an audible difference between such pitches. 
         [0018]    As little as one tone may be contained within a tone group in another embodiment, in which case the intra-group temporal spacing would go to zero and the inter-group temporal spacing would be the only spacing between tones. 
         [0019]    Sample tonal patterns with varying pitch sequences of various embodiments are shown in  FIG. 3 ,  FIG. 4 ,  FIG. 5 , and  FIG. 6 . 
         [0020]    Tonal patterns are comprised of at least one tone group and are differentiated by the number of tones and temporal spacings between the tones within the tone groups (intra-group temporal spacing) and the temporal spaces between repeated tone groups (inter-group temporal spacing). As an example,  FIG. 3 ,  FIG. 4 , and  FIG. 5  illustrate the same tonal patterns but contain different pitch tones or different pitch sequences. Silent periods or silent times of a tonal pattern refer to times when no tonal alarm is present; however, silent periods or times do not preclude the presence of a non-tonal emission such as a verbal output. 
         [0021]    In one embodiment, verbal output is used to describe the type of condition sensed or the location of the detector sensing the condition, or both, or instructions on how to remain safe in accordance with the sensed to condition. At least one word is used to describe the type of ambient condition or location of the ambient condition sensed. In this embodiment, the control electronics with audio pitch control  20  contains voice synthesis circuitry to electronically output a recorded verbal message held in memory  25  to the audio output transducer  30  or additional audio output transducer  40  when there are silent periods in the tonal pattern. The control electronics with audio pitch control  20  contains circuitry to determine which ambient sensor within the ambient condition detector sensed the condition in embodiments with a plurality of different ambient condition sensors and can thereby output the appropriate verbal message to indicate the type of condition sensed. 
         [0022]    In another embodiment having verbal output, the optional location selector  35  is present and connected to the control electronics with audio pitch control  20  where the location selector  35  is used to select the location where the ambient condition detector is installed, said location information is stored within the control electronics with audio pitch control  20 . In this embodiment, the optional memory for verbal messages  25  is present and includes memory space to store at least one verbal message indicative of the installation location of the ambient condition detector. Example location messages include but are not limited to “basement”, “kitchen”, “living room”, “bedroom”, utility room”, “second floor”, etc. When the ambient condition sensor  10  senses an ambient condition, the control electronics with audio pitch control  20  outputs a tonal pattern to the audio output transducer  30 , whereby during at least one silent period occurring within the tonal pattern, at least one word of a verbal message is output to indicate the location of the ambient condition detector sensing the ambient condition. The optional location selector  35  is accessible to the user and may take the form, without limitation, of a DIP switch, a jumper(s), a rotary switch, an electrical contact, or momentary switch in various embodiments. Only embodiments which emit verbal output include optional memory for verbal message  25 . 
         [0023]    In at least one embodiment, an optional additional audio output transducer(s)  40  may be included to most effectively emit specific pitches of the alarm tones. This may be particularly useful, but not required, where piezoelectric elements are used for the audio output devices or in embodiments where verbal output is used. The audio output device  30  is a speaker in at least one embodiment. 
         [0024]    In one embodiment, two different ambient condition sensors are included within the same unit to sense two different ambient conditions wherein the tonal patterns for each sensed condition are different and the pitches of the tones, within the respective tonal patterns, may be the same or distinctly different. In one such embodiment, one ambient condition sensor is a smoke or fire sensor and the other sensor is a gas sensor such as carbon monoxide or natural gas. 
         [0025]    The power supply  50  is a battery power supply in one embodiment, an AC power supply in another embodiment, an AC power supply with battery back-up in another embodiment, and a hardwired DC power supply in another embodiment. The power supply  50  provides electrical power to the electrical components of the ambient condition detector unit. 
         [0026]    Another embodiment is an ambient condition detector unit shown in  FIG. 2  where an ambient condition sensor  110  is connected to control electronics  120  such that sensing of an ambient condition by ambient condition sensor  110  provides an input signal to the control electronics  120 . The control electronics  120  is microprocessor based in one embodiment and may be ASIC based in another embodiment and may contain electronic memory for one or more alarm tonal patterns containing one or more tone pitches included within tone groups or between successive tone groups and one or more silent periods within the tonal patterns. The control electronics  120  may further include electronic storage to store an identifier, such as an electronic memory pointer, to indicate which tonal output is selected by the user through the audio output pitch selector  150 . Alternatively, in another embodiment, the configuration or position of the audio output pitch selector  150  is read by the control electronics  120  to determine the user&#39;s selection of the desired tonal output. The control electronics  120  sends an output signal to the audio output transducer  130  such that the audio output transducer  130  emits a tonal pattern having at least one pitch controlled by the control electronics  120  as electronically directed by the input of the audio output pitch selector  150 . The control electronics  120  controls the tonal pattern and tone pitch in one embodiment. Alternatively, the audio output transducer  130  has included circuitry to control the pitch of the tonal output, but selection of pitch is controlled by the control electronics  120  as electronically directed by the input of the audio output pitch selector  150 . 
         [0027]    A user may interface with the audio output pitch selector  150  in various ways in various embodiments. The audio output pitch selector  150  is a multi-position switch in one embodiment, a DIP switch in another embodiment, a variable resistor in another embodiment, a momentary switch in another embodiment, a jumper in another embodiment, and a receiver of radiant energy, such as but not limited to an infrared light receiver or radio frequency, in another embodiment. The audio output selector  150  is connected to the control electronics  120 . In an embodiment where the audio output pitch selector  150  comprises an infrared energy receiver or radio frequency signal receiver, the electronics contained therein decodes the incoming signal to interface to the control electronics  120  to select the tone pitch desired. 
         [0028]    In one embodiment, user interfacing with the audio output pitch selector  150  permits the user to select at least one pitch of a tone within the emitted tonal pattern from the audio output transducer  130  by activating the audio output pitch selector  150  when the desired pitch is heard by the user during a set-up mode of the ambient condition detector (often as part of installation of the detector) as the control electronics  120  drives the audio transducer  130  to play through a menu of pre-programmed pitches and/or tonal patterns of varying pitch from which the user may select. The menu is stored within the control electronics  120 . The tonal patterns may include silent periods. At least one software or firmware program or similar electronic instruction is stored within the control electronics  120  to output a range of tone pitches to the audio output transducer  130  and to identify the user-selected pitch when selected by the user during ambient condition detector set-up mode and/or installation as shown in  FIG. 7  as a non-limiting example. 
         [0029]    In one embodiment, during a set-up mode of the ambient condition detector, the control electronics plays through the menu of pre-programmed tonal patterns which comprise at least two distinctly different pitch tones. When the user hears the tonal pattern with the desired pitch content, the user activates the audio output pitch selector  150  to store that selection identifier (electronic memory location pointer in one embodiment) into the memory of the control electronics  120  (see  FIG. 8 ). 
         [0030]    In another embodiment, the audio output pitch selector  150  is used to permit the user to make a selection from a choice of two or more distinctly different pitch tone groups, each tone group comprised of equal pitch tones, within tonal patterns factory-stored within the control electronics  120 . The tone group choices may include silent periods. As a non-limiting example in one embodiment, the user may employ the audio output pitch selector  150  to choose from low, medium, and high pitch selections for the output tonal pattern where low, medium, and high may refer to pitch frequencies on the order of 1000 Hz, 2000 Hz, and 3000 Hz, respectively, as just one example.  FIG. 9  illustrates one example of the flow diagram for a user selected pitch for one embodiment with low, medium, and high pitches. This diagram may apply to more or less than three pitch selections. In this embodiment, the audio output pitch selector  150  instructs the control electronics  120  which factory-stored, tonal pitch sequence to send to the audio output transducer  130  when an ambient condition is detected. 
         [0031]    In another embodiment, user interfacing with the audio output pitch selector  150  permits the user to select from two or more alarm tones each comprising at least two distinctly different tonal pitches emitted from the audio output transducer  130 . At least one software or firmware program or similar electronic instruction to yield the at least two distinctly different tonal pitches within tone groups or between tone groups is stored electronically within the control electronics  120  in one embodiment. One flow chart illustration of an electronic instruction is shown in  FIG. 8  as a non-limiting example. In at least one embodiment, a tone group comprises tones separated by at least one silent period. The time between repeating of the tone group is longer than the silent periods within the tone group. For example, in  FIG. 3 ,  FIG. 4 , and  FIG. 5  the first three tones illustrated in each figure comprise a first tone group and the second three tones illustrated comprise a second tone group separated from the first tone group by at least twice the time present between any two tones within a tone group. Times between tone groups are called inter-group temporal spacing  210 ,  310 , and  410  and times between individual tones within a tone group are call intra-group temporal spacing  200 ,  300 , and  400 . It is noted that the illustrative example of three tones in a tone group as shown in  FIG. 3  is not intended to be limiting. More or less than three tones may comprise a tone group, in general as is shown in an example in  FIG. 6 . 
         [0032]    As little as one tone may be contained within a tone group in one embodiment, in which case the intra-group temporal spacing would go to zero and the inter-group temporal spacing would be the only spacing between tones. 
         [0033]    In at least one embodiment, the tonal pattern comprises tone groups with intra-group temporal spacing of a first amount and inter-group temporal spacing of a second amount wherein the second amount is at least twice as much as the first amount. Sample tonal patterns with varying pitch sequences of various embodiments are shown in  FIG. 3 ,  FIG. 4 ,  FIG. 5 , and  FIG. 6 . 
         [0034]    Tonal patterns are comprised of at least one tone group and are differentiated by the number of tones and temporal spacings between the tones within the tone groups (intra-group temporal spacing) and the temporal spaces between repeated tone groups (inter-group temporal spacing). As an example,  FIG. 3 ,  FIG. 4 , and  FIG. 5  illustrate the same tonal pattern but contain different pitch tones or different pitch sequences. Silent periods or silent times of a tonal pattern refer to times when no tonal alarm is present; however, silent periods or times do not preclude the presence of a non-tonal emission such as a verbal output. 
         [0035]    In one embodiment, verbal output is used describe the type of condition sensed or the location of the detector sensing the condition, or both, or instructions on how to remain safe in accordance with the sensed to condition. At least one word is used to describe the type of ambient condition or location of the ambient condition sensed. In this embodiment, the control electronics  120  contains voice synthesis circuitry to electronically output a recorded verbal message held in memory  125  to the audio output transducer  130  or additional audio output transducer  140 . Only embodiments which emit verbal output include optional memory for verbal message  125 . The control electronics  120  contains circuitry to determine which ambient sensor within the ambient condition detector sensed the condition in embodiments with a plurality of different ambient condition sensors and can thereby output the appropriate verbal message to indicate the type of condition sensed. 
         [0036]    In another embodiment having verbal output, the optional location selector  135  is present and connected to the control electronics  120  where the optional location selector  135  is used to select the location where the ambient condition detector is installed, said location information is stored within the control electronics  120 . In this embodiment, the optional memory for verbal messages  125  is present and includes memory space to store at least one verbal message indicative of the installation location of the ambient condition detector. Example location messages include but are not limited to “basement”, “kitchen”, “living room”, “bedroom”, utility room”, “second floor”, etc. When the ambient condition sensor  110  senses an ambient condition, the control electronics  120  outputs a tonal pattern to the audio output transducer  130 , whereby during at least one silent period occurring within the tonal pattern, at least one word of a verbal message is output to indicate the location of the ambient condition detector sensing the ambient condition. The optional location selector  135  is accessible to the user and may take the form, without limitation, of a DIP switch, a jumper, a multi-position switch, an electrical contact, or momentary switch in various embodiments. Only embodiments which emit verbal output include optional memory for verbal message  125 . 
         [0037]    In at least one embodiment, an additional audio output transducer(s)  140  may be included to most effectively emit specific pitches of the alarm tones. This may be particularly useful, but not required, where piezoelectric elements are used for the audio output devices or in embodiments where verbal output is used. An audio output device  130  is a speaker in at least one embodiment. 
         [0038]    The power supply  160  is a battery power supply in one embodiment, an AC power supply in another embodiment, an AC power supply with battery back-up in another embodiment, and a hardwired DC power supply in another embodiment. The power supply  160  provides electrical power to the electrical components of the ambient condition detector unit. 
         [0039]    Various sample pitch sequences of tonal patterns are illustrated in  FIG. 3 ,  FIG. 4 ,  FIG. 5 , and  FIG. 6  for various embodiments and are in no way intended to be limiting but serve as exemplary tonal patterns having at least two distinctly different pitch tones which may output by the ambient condition detector. While the sample, triple tonal groupings ( FIGS. 3-5 ) are most relevant to smoke or fire detector embodiments of the ambient condition detector, similar variable pitch tonal patterns may be output for other ambient condition detectors such as gas detectors which may output a quadruple tonal grouping within one embodiment ( FIG. 6 ). 
         [0040]      FIG. 3  illustrates an inter-group alternating pitch sequence for a tonal pattern of one embodiment where the inter-group temporal spacing  210  is at least twice the amount of the intra-group temporal spacing  200 . 
         [0041]      FIG. 4  illustrates an inter-group ramping pitch sequence for a tonal pattern of one embodiment where the inter-group temporal spacing  310  is at least twice the amount of the intra-group temporal spacing  300 . 
         [0042]      FIG. 5  illustrates an intra-group alternating pitch sequence for a tonal pattern of one embodiment where the inter-group temporal spacing  410  is at least twice the amount of the intra-group temporal spacing  400 . 
         [0043]      FIG. 6  is an example tonal pattern illustrating an inter-group alternating pitch sequence used in one gas detector embodiment. Other pitch variance sequences similar but not limited to those shown in  FIG. 3 ,  FIG. 4  and  FIG. 5  (inter-group alternating, intra-group ramping and intra-group alternating, respectively) may be used for gas detectors in other embodiments. Still other tonal patterns and pitch sequences may be used for other ambient conditions. 
         [0044]    In at least one embodiment, a housing is used to enclose components such as, but not limited to, the control electronics, the ambient condition sensor, and the audio output transducer. The housing permits the ambient condition sensor to sense at least one ambient condition originating outside of the housing through openings or optical sensors viewing through the housing wall as well as with sensors within the housing such as, but not limited to, smoke sensors, fire sensors, thermal sensors, gas sensors, vibration sensors, motion sensors, and radiation sensors. 
         [0045]    The various embodiments described above are merely descriptive and are in no way intended to limit the scope of the invention. Modification will become obvious to those skilled in the art in light of the detailed description above, and such modifications are intended to fall within the scope of the appended claims. It is to be understood that no limitation with respect to the specific apparatus illustrated herein is intended or should be inferred.
The pitch of tones within tonal patterns emitted by ambient condition detector units and systems in the alarm or testing state is not always optimum to be heard by a wide range of users. An ambient condition detector outputs an alarm comprising a tonal pattern whereby a user can select at least one pitch tone emitted within a tonal pattern alarm when the detector senses an ambient condition. Options include verbal output.