Abstract:
A measurement system and method combine an audio announcement system with a plurality of spaced apart wirelessly coupled devices which evaluate speech intelligibility of audio output from loudspeakers of the audio announcement system. Processing can take place at some or all of the devices as well as at a common control element. Evaluations can be based on use of a method which maps to a Common Intelligibility Scale.

Description:
CROSS REFERENCE TO RELATED APPLICATION  
       [0001]     This application is a continuation-in-part of U.S. patent application Ser. No. 10/740,200 filed Dec. 18, 2003 and entitled, “Intelligibility Measurement of Audio Announcement Systems.” 
     
    
     FIELD OF THE INVENTION  
       [0002]     The invention pertains to systems and methods of evaluating the quality of audible output provided to assist or inform individuals in a region. More particularly, the intelligibility of provided audio is evaluated in wireless units by sensing a plurality of predetermined audible outputs, from an audio output transducer, and, evaluating intelligibility thereof on a per region basis.  
       BACKGROUND  
       [0003]     It has been recognized that speech being projected or transmitted into a region is not necessarily intelligible merely because it is audible. In many instances such as sports stadiums, airports, public buildings and the like, speech delivered into a region may be loud enough to be heard but it may be unintelligible. Such considerations apply to audio announcement systems in general as well as those which are associated with fire safety, building or regional monitoring systems.  
         [0004]     Relative to the latter, it has been known to conduct intelligibility testing in connection with such systems by having an installer or technician walk through a building or region being evaluated and listen to output from various speakers of the public address or alarm evacuation system to assess the intelligibility of the instructions or information being output by such devices. In an alternate mode, portable intelligibility analyzers can be carried through the building to each region of interest to provide a quantitative measure of speech intelligibility.  
         [0005]     It also has been recognized that testing as described above requires that the installer or technician must literally move through most of the building or region being evaluated to listen or measure the intelligibility of speech signals being delivered in each region. This process is not only time consuming but expensive especially in large buildings. Additionally, when a floor or a portion of the region is being redecorated or built out for a different tenant, that portion of the building or region must be re-evaluated at additional cost of time and money after the construction and/or build-out has been completed.  
         [0006]     It would be desirable to in some way make use of some or all of the existing equipment of such systems to improve intelligibility testing/evaluation. In such event, more frequent evaluation/testing could be conducted throughout the region or building monitored.  
         [0007]     It also has been recognized that there is a benefit in moving from subjective evaluation of the intelligibility of speech in a region toward a more quantitative approach which, at the very least, provides a greater degree of repeatability. A standardized quantitative measure of speech intelligibility is the Common Intelligibility Scale (CIS). Various machine-based methods such as Speech Transmission Index (STI), Speech Transmission Index Public Address (STI-PA), Speech Intelligibility Index (SII), Rapid Speech Transmission Index (RASTI), and Articulation Loss of Consonants (AL cons ) can be mapped to the CIS. These test methods have been developed for use in evaluating speech intelligibility automatically and without any need for human interpretation of the speech intelligibility.  
         [0008]     In the majority of machine-based testing a noise or noise-like signal is amplitude modulated at various rates. The signal is transmitted from a source, such as a loud speaker, into a portion of a region of interest. The signals are detected, for example by an acoustic sensor. The received signals are analyzed by comparing the depth of modulation thereof with that of the test signal. Reductions in modulation depth of received signals are associated with loss of intelligibility.  
         [0009]     Details of machine-based evaluations have been published and are available for example in “The Modulation Transfer Function In Room Acoustics as a Predictor of Speech Intelligibility” by Steeneken and Houtgast, Acustica V28, PG66-73 (1973) and “A Review of the MTF Concept in Room Acoustics and its Use for Estimating Speech Intelligibility in Auditoria” by Steeneken and Houtgast, Institute for Perception TNO, Soesterberg, the Netherlands (1984).  
         [0010]     The above described evaluation process can be carried out by any one of a variety of publicly available analysis programs as would be available to those of skill in the art. One such program has been disclosed and discussed in an article, “The Speech Transmission Index Program is Up and Running”, Lexington Center and School for the Deaf, V3.1 (Sep. 9, 2003). Other programs for evaluating CIS-mappable intelligibility evaluation are available as would be known to those of skill in the art.  
         [0011]     There thus continues to be on ongoing need for improved, more efficient, intelligibility testing in connection with fire safety/evacuation voice announcement systems. It would be desirable if the recognized benefits of CIS-mappable processing could be incorporated into such systems to improve intelligibility testing thereof. It also would be desirable to be able to incorporate such functional capability in a way that takes advantage of easily installable, wireless device which are intended to be distributed throughout a region being evaluated so as to minimize additional installation cost and/or equipment needs. Preferably such functionality could not only be incorporated into the devices being installed, but also could be cost effectively incorporated as upgrades to existing systems. 
     
    
     BRIEF DESCRIPTION OF THE DRAWING  
       [0012]      FIG. 1  is a block diagram of an intelligibility evaluation system in accordance with the invention;  
         [0013]      FIG. 2A  is a block diagram illustrative of a device incorporating one or more ambient condition sensors and one or more acoustic sensors and usable in the system of  FIG. 1 ;  
         [0014]      FIG. 2B  is a block diagram of an exemplary device incorporating one or more acoustic sensors and usable in the system of  FIG. 1 ;  
         [0015]      FIG. 2C  is a block diagram of an exemplary local processing device usable in the system of  FIG. 1 ; and  
         [0016]      FIG. 3  is a block diagram of a wireless intelligibility evaluation device. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0017]     While this invention is susceptible of an embodiment in many different forms, there are shown in the drawing and will be described herein in detail specific embodiments thereof with the understanding that the present disclosure is to be considered as an exemplification of the principles of the invention. It is not intended to limit the invention to the specific illustrated embodiments.  
         [0018]     In accordance with the invention, intelligibility evaluation can be incorporated in an audio announcement system. In one embodiment, devices incorporating one or more acoustic sensors can be located throughout a region or building being evaluated. Circuitry associated with the respective acoustic sensors can carry out CIS-mappable measurement processing of audio received from one or more speakers, which would be associated with building or regional audio announcement systems. The devices can include a wireless transceiver to receive commands and to communicate CIS-mappable measurements to a nearby wired system. Wireless devices can function as repeaters for one another thereby increasing the size of the region which can be evaluated.  
         [0019]     In one aspect, to carry out an intelligibility evaluation, a sequence of CIS-mappable test signals are delivered from one or more loudspeakers. The signals can be received by one or more acoustic sensors and then, locally, evaluated using a CIS-mappable process. Alternately, the signals received by one or more acoustic sensors can be communicated to a common location for evaluation.  
         [0020]     Where the evaluation is conducted at least in part locally at the respective acoustic sensor(s), the calculated CIS-mappable value or other value, can be transmitted wirelessly directly or via another device to a control console for storage, operator review, and evaluation.  
         [0021]     It also will be understood that wireless devices can receive and retransmit CIS-mappable values and zone specifying information from other wireless devices, to associated wired devices, or a regional monitoring system. This repeater-like operation will extend the range of the transceivers of the respective wireless devices.  
         [0022]     The system enables an operator, from a common control console, to evaluate speech intelligibility throughout the building or region or only in certain zones at any given time. Additionally, regular evaluations can be scheduled and carried out automatically during off-peak hours such as overnight, on weekends, and the like. A parent application hereto, No. 10/740,200 filed Dec. 18, 2003 assigned to the assignee hereof is incorporated herein by reference.  
         [0023]      FIG. 1  illustrates a system  10 , which could be a fire alarm system of a known type usable for monitoring a region R. The system  10  includes common control circuitry or a fire alarm control panel  12 . The system  10  can include a plurality of ambient condition detectors  14 . The detectors  14  could for example be smoke detectors, thermal detectors or gas detectors or combinations thereof all without limitation. Those of skill in the art would understand the specific types of structures which are available to implement such detectors. Units such as  18 - i  represent local processing devices, discussed subsequently.  
         [0024]     The detectors  14  are in communication with the control panel  12  via a wired or wireless medium indicated generally as  16 . In one embodiment, some of the detectors, such as  14 - 1 ,  14 - 3  and  14 - n  also include acoustic sensor(s) indicated generally as  20 - 1 ,  20 - 3  and  20 - n . The acoustic sensor(s)  20 - 1  . . .  20 - n  could be incorporated in only some or in all of the detectors  14 .  
         [0025]     As discussed in more detail subsequently, signals received via acoustic sensor(s)  20 - 1  . . .  20 - n  could be processed partially or completely at the respective detector  14 - 1  . . .  14 - n . Alternatively, some or all of the processing could be carried out at various system devices  18 - i  or at control panel  12 . It will be understood that signals from acoustic sensor(s)  20 - 1  . . .  20 - n  could be transmitted in a variety of ways, wirelessly or via medium  16 , to control panel  12  all without limitation.  
         [0026]     Region R can also incorporate an audio announcement system  30  which could be coupled to or be a part of the control panel  12 . The audio announcement system  30  incorporates one or more loudspeakers  32 - 1  . . .  32 - m  located throughout the region R. The speakers  32 - 1  . . .  32 - m  could be used, as would be understood by those of skill in the art, for audibly outputting routine messages to people working or present in the region R. Alternately, the speakers  32 - 1  . . .  32 - m  could be used, in connection with system  10  to advise individuals in the region R of a hazardous condition, such as a fire or the like and provide information and instructions thereto.  
         [0027]     System  30  also can include coupled thereto one or more devices  34  such as  34 - 1  . . .  34 - k  located throughout the region R in addition to or in lieu of the detector(s)  14 . Devices  34  can be coupled to system  30  and/or the alternative processing nodes  18 - i  wirelessly or by a wired medium  36 . Devices  34  include one or more acoustic sensor(s)  60 , such as  60 - i.    
         [0028]     A source of test signals  40  could be coupled to audio announcement system  30  either acoustically or electrically, without limitation, to provide intelligibility test signals to be output via speakers  32  throughout the region R. The test signals could be, for example, STI-test signals, RASTI, SII test signals, subsets thereof or other types of standardized test signals usable to evaluate CIS-mappable intelligibility as would be understood by those of skill in the art.  
         [0029]     In response to the output from the speakers  32 , acoustic sensor(s)  20 ,  60 , receive audio input corresponding thereto based on their respective physical relationships with the members of the plurality  32 . The microphones  20 ,  60  could also be coupled to local processing circuitry to carry out CIS-mappable evaluation processing. The evaluation results can then be communicated to control panel  12  via medium  36 . Alternately, modular devices  18 - i  can receive the local audio from units  34 - i , to formulate, at each location, an STI value, an RASTI value, an SII value or any other type of CIS-mappable value without limitation.  
         [0030]     The respective CIS-mappable values can be determined at the respective acoustic sensor locations and transmitted via media  16  or  36  respectively to control panel  12  and/or audio announcement system  30 . A zone or device identifier can also be transmitted along with the respective CIS-mappable value(s). The respective values can be presented, for example on graphical display  42  for review by operational personnel. Graphical display  42  may communicate with various parts of the system via wired or wireless communication. A storage unit  44  can be included to store evaluation results. It will be understood that display  42  and storage unit  44  can also be coupled or interfaced to control panel, or control circuits  12 .  
         [0031]     Alternately, some or all of the CIS related processing could be carried out at control panel  12  without departing from the spirit and scope of the invention. In such an embodiment, signals from the acoustic sensor(s) could be digitized and communicated using a digital protocol to panel  12 .  
         [0032]     To improve regional coverage particularly where wired media, such as  16  or  36  are not readily available, wireless devices such as  34 - m   1 ,  m   2 ,  m   3  . . .  mi  can be installed. Such devices include an acoustic sensor  60 - mi , coupled to local processing circuitry to carry out local processing to produce a CIS-mappable intelligibility value.  
         [0033]     Each of the devices  34 - mi  include a wireless transducer, such as  38 - mi , for wireless reception and transmission of values. The devices  34 - mi  are not only in wireless communication with one another, they can also be in wireless communication with units such as  34 - i ,  34 - k  which are in wired communication with  12 .  
         [0034]     Wireless units can thus be installed throughout region R to improve speech intelligibility evaluation. They can communicate directly with wired devices, fire alarm control panels, audio announcement systems and the like. They can also function as repeaters for those wireless devices that are too far from the wired system. Such devices can transmit, for example, the calculated CIS-mappable values along with an ID code or zone identifier.  
         [0035]     The above described intelligibility evaluation process can be carried out automatically throughout the region R at any appropriate time and the results stored and presented to the operation personnel subsequently. It also has the advantage that if the space in the region R is in part reconfigured, the process can be again initiated and carried out to determine or establish the intelligibility of audio throughout the revised portion of the region R.  
         [0036]     Because the evaluation involves interactions between audio from speakers  32  which is in turn sensed by acoustic sensor(s)  20 ,  60  as well as those of wireless devices such as  34 - m   1 ,  m   2 ,  m   3  . . .  mi , no operating personnel need travel through the region R as part of the evaluation process. Finally, the CIS-mappable values provide a quantitative assessment of intelligibility and eliminate subjective influences which may be present where individuals are attempting to evaluate intelligibility based on their own perceptions.  
         [0037]     It will also be understood that none of the exact details of the devices such as detectors  14 ,  34 , local processing devices, such as  18 - i , acoustic sensor(s)  20 ,  60 ,  34 - mi , or speakers  32  represent limitations of the present invention. Similarly, the numbers of such devices are also not limitations of the present invention. Finally, the location of the CIS-mappable processing, which can in part be located at each of the respective detectors  14 , local processing nodes  18 , wireless units  34 - mi , or, at the control panel  12 , all without limitation, is not a limitation of the invention.  
         [0038]     The control panel  12  could also incorporate a transceiver  72   a  and wireless transducer  72   b  for communication with wireless devices as described above. Wireless transmissions can include RF or infrared, or other types of wireless communications all without limitation.  
         [0039]      FIG. 2A , a block diagram illustrates additional details of a representative detector  14 - i  having a housing  48  which carries a acoustic sensor  20 - i  and provisions for connections to several optional external acoustic sensor(s) such as  20 - i ′. Housing  48  can be mounted on or adjacent to a selected surface in region R. Detector  14 - i  includes at least one ambient condition sensor  50  which could be implemented as a smoke sensor, a flame sensor, a thermal sensor, a gas sensor or a combination thereof.  
         [0040]     Outputs from sensor  50  and acoustic sensor(s)  20 -,  20 - i ′, are coupled to control circuitry  52  which could be implemented, in part, with hard wired circuits or a processor  52   a  for executing pre-configured software or instructions  52   b . Instructions  52   b  could include processing instructions for establishing a CIS-mappable value or subsets thereof, all without limitation in response to incoming audio sensed at acoustic sensor at  20 - i.    
         [0041]     Outputs from circuits  52  can include values indicative of outputs from sensor  50  as well as acoustic sensor  20 - i  or, the processed intelligibility values in whatever form is preferred. Those outputs are coupled via interface circuitry  54  to medium  16  for transmission to control system or fire alarm control panel  12 . It will also be understood that the interface  54  can carry out bi-directional communication between the medium  16  and the detector  14 - i  if desired, all without limitation.  
         [0042]      FIG. 2B  illustrates, in block diagram form, a member  34 - i  or  34 - k  of the plurality  34 . Device  34 - i  includes a housing  58  which is mountable on a selected surface in the region R. Housing  58  may include an acoustic sensor, such as  60 - i  and provisions for connections to several optional external acoustic sensors  60 - i ′ which are in turn coupled to control circuits  62 . Circuits  62  could include both hard wired circuits and/or a processor  62   a  for executing pre-stored instructions or logic  62   b , as desired, for carrying out CIS-mappable processing and producing a value internally to the device  34 - i ,  34 - k . The control circuits  62  can in turn transfer the generated value, via interface circuit  64  and medium  36  to control panel  12  for analysis and presentation as desired on display  42 , for example.  
         [0043]     The interface circuitry  64  can include a port for connection with a wired medium such as medium  36 . Additionally, it can include a wireless transducer  38   i  or  38   k  respectively in devices  34   i, k  and an associated transceiver  44 - i, k . Wireless CIS-mappable values/zone identification signals from any or all of the units  34 - mi  can be received by the respective wireless transducer(s)  38   i ,  38   k  (and associated transceiver). Those signals can in turn be communicated via wired medium  36  to control panel  12  for presentation.  
         [0044]      FIG. 2C  is a block diagram of a local processing device  18 - i . Previously described components have been assigned the same identification numeral. Device  18 - i  could be coupled to either of media  16 ,  36  as desired. Local circuitry and software carry out CIS-mappable processing in response to received audio. Devices  18 - i  could also carry out processing of signals received at other devices such as  14  or  34 . Control circuits  72 , which can include a processor  72   a  and software  72  band/or other circuitry or logic to process received audio and generate a CIS-mappable value(s) as described above. They can communicate via interface circuits  74  using a wired medium, such as  16  or  36 , or wirelessly  74   a.    
         [0045]     It will be understood that the implementations illustrated for devices  14 - i  and  34 - i  are exemplary only. Variations can be incorporated therein, as would be understood by those of skill in the art, depending on the specific application all without departing from the spirit and scope of the present invention. Among other variations, the acoustic sensors are exemplary only. Other forms of audio input transducers come within the spirit and scope of the invention.  
         [0046]      FIG. 3  is a block diagram of one of the wireless devices  34 - mi . The device  34 - mi  is carried by a housing  80  which is mountable on any selected surface in the region R. Housing  80  can incorporate and carry an acoustic sensor  60 - mi . It can also incorporate provisions for connections to several optional external acoustic sensors if desired.  
         [0047]     The acoustic sensor(s)  60 - mi , are in turn coupled to control circuits  82 . Circuitry  82  can incorporate a programmed processor  82   a  for executing pre-stored instructions  82   b  for carrying out CIS-mappable processing and producing a value to the device  34 - mi . The value can in turn be coupled via interface and transceiver  84 , wirelessly via transducer  38 - mi  to one or more of the devices such as  34 - i ,  34 - k  (both in wired communication via medium  36  with unit  30 ), or any of the other wireless units which can function as repeaters such as  18 - i ,  34 - m   1 ,  34 - m   2  . . .  34 - mn.    
         [0048]     The wireless device  34 - mi  can also incorporate within housing  80  a power supply  86  which could for example be implemented as a self-contained energy supply, or, alternately receive electrical energy from an external source. The wireless device  34 - mi  is particularly advantageous in that it can be located anywhere in the region R independently of the wired medium  36  and without any need for an external source of electrical energy. Hence, the region R can be saturated with wireless units to promote intelligibility testing and evaluation at locations where heretofore it has been inconvenient to do so.  
         [0049]     It will be understood that neither of the exact details of the wireless devices  34 - mi  nor the details of the wireless communication protocol described above, are limitations of the present invention.  
         [0050]     From the foregoing, it will be observed that numerous variations and modifications may be effected without departing from the spirit and scope of the invention. It is to be understood that no limitation with respect to the specific apparatus illustrated herein is intended or should be inferred. It is, of course, intended to cover by the appended claims all such modifications as fall within the scope of the claims.