Abstract: Disclosed herein are an X-ray imaging apparatus for forming an X-ray image having reduced noise by correcting errors according to characteristics of each of a plurality of pixels and a control method therefor. The X-ray imaging apparatus includes an X-ray generator to generate X-rays and irradiate the generated X-rays, an X-ray detector to detect the irradiated X-rays and output X-ray data by counting the number of photons having an energy that is equal to or greater than threshold energy among photons contained in the detected X-rays, for each of a plurality of pixels; a function acquisition unit to acquire calibration functions for the respective pixels using X-ray data output for a plurality of predesigned phantoms, and an image correction unit to correct an X-ray image of an object on a per pixel basis using the acquired calibration functions.

Abstract: Radiosurgery systems are described that are configured to deliver a therapeutic dose of radiation to a target structure in a patient. In some embodiments, inflammatory ocular disorders are treated, and in some embodiments, other disorders or tissues of a body are treated with the dose of radiation. In some embodiments, target tissues are placed in a global coordinate system based on ocular imaging. In some embodiments, a fiducial marker is used to identify the location of the target tissues.

Abstract: A system for eliminating image artifacts caused by electromagnetic interference (EMI) on a portable digital x-ray detector that is capable of non-contact wireless inductively coupled power transfer and capacitively coupled communication and data transfer. An X-ray imaging system comprising a portable digital X-ray detector inductively and capacitively coupled to a power source and communication device that is coupled to a detector receptacle of the X-ray imaging system when the portable digital X-ray detector is located within the detector receptacle to transfer power from a power supply of the power source and communication device to the portable digital X-ray detector and transfer communication and data between the power source and communication device and the portable digital X-ray detector.

Abstract: The radiographic image photographing system includes an information acquisition member which acquires information on the radiographic image photographing device from an information presentation member of the radiographic image photographing device in a non-contact manner. When the information acquisition member makes the notification of the acquired information on the radiographic image photographing device, the management apparatus notifies the wireless communication member of the radiographic image photographing device of an identifier dedicated to an access point correlated with the information acquisition member. The wireless communication member of the radiographic image photographing device conducts wireless communication with the access point using a general-purpose identifier in a default state, and using the identifier dedicated to the access point after receiving the notification of the identifier dedicated to the access point from the management apparatus.

Abstract: A system for eliminating image artifacts caused by electromagnetic interference (EMI) on a portable digital x-ray detector that is capable of non-contact wireless inductively coupled power transfer. An X-ray imaging system comprising a portable digital X-ray detector having detector circuitry coupled to at least one receiver coil, and a power source including a power supply coupled to a signal filter device and coupled to at least one transmitter coil, wherein the power source is coupled to a detector receptacle of the X-ray imaging system, and wherein the at least one receiver coil and the at least one transmitter coil are inductively coupled to each other when the portable digital X-ray detector is located within the detector receptacle of the X-ray imaging system to transfer power from the power supply to the detector circuitry.

Abstract: An electrically heated planar cathode for use in miniature x-ray tubes may be spiral design laser cut from a thin tantalum alloy ribbon foil (with grain stabilizing features). Bare ribbon is mounted to an aluminum nitride substrate in a manner that is puts the ribbon in minimal tension before it is machined into the spiral pattern. The spiral pattern can be optimized for electrical, thermal, and emission characteristics.

Abstract: A technique for indirectly measuring the degree of alignment of a beam in an electron-optical system including aligning means, focusing means and deflection means. To carry out the measurements, a simple sensor may be used, even a single-element sensor, provided it has a well-defined spatial extent. When practiced in connection with an X-ray source which is operable to produce an X-ray target, further, a technique for determining and controlling a width of an electron-beam at its intersection point with the target.

Abstract: A composite crystal array for a pixelated gamma camera and a method of making thereof, which are adapted to a photoelectric matrix that consists of position sensitive photomultiplier elements, in which the photoelectric matrix is divided into sensible and non-sensible areas with a geometric distribution, so as to set a ratio of a segmented region; a configuration detail of a partial optical splitting crystal array and a configuration detail of a whole optical splitting crystal array are set according to the ratio of the segmented region; and the partial optical splitting crystal array and the whole optical splitting crystal array are made according to the two configuration details, and two kinds of crystal arrays are combined to form a whole crystal array for the pixelated cameras according to the segmented region, so that the effective area of the pixelated camera is kept continuous and the resolution thereof is kept uniform.

Abstract: An adaptive X-ray filter for varying a local intensity of X-ray radiation includes a first chamber containing a magnetorheological or electrorheological first liquid, a second chamber containing a second liquid that absorbs X-ray radiation, and a flexible membrane that separates the first chamber from the second chamber. Using the flexible membrane, a layer thickness ratio of the first liquid and the second liquid may be varied. A heating apparatus that heats the second liquid is arranged in the adaptive X-ray filter. The second liquid is a liquid metal.

Abstract: An electronic cassette for radiographic imaging has an enclosure, an imaging detection panel disposed in the enclosure and configured to convert an amount of radiation into an electric signal, a circuit unit disposed in the enclosure and configured to read an electric signal from the imaging detection panel by supplying a driving signal to the imaging detection panel, and a holding base disposed in the enclosure and configured to support the imaging detection panel. The holding base supports the imaging detection panel on a first surface as a radiation incident side and supports the circuit unit on a second surface on an opposite side to the first surface. The holding base includes a carbon fiber laminated plate having a metal layer inserted in lamination layer, and the metal layer is electrically connected to ground of the circuit unit.

Abstract: A method, computer program product, and computer system for inferring quality of unified telephony calls based on real-time bi-directional exploitation of a full reference algorithm. A client copy of an audio file may be received from a client device associated with a unified telephony call. The client copy of the audio file may be compared to a local copy of the audio file using a reference algorithm. A quality of service associated with the client device may be determined based upon, at least in part, a difference between the client copy of the audio file and the local copy of the audio file.

Abstract: A method, computer program product, and computer system for inferring quality of unified telephony calls based on real-time bi-directional exploitation of a full reference algorithm. A client copy of an audio file may be received from a client device associated with a unified telephony call. The client copy of the audio file may be compared to a local copy of the audio file using a reference algorithm. A quality of service associated with the client device may be determined based upon, at least in part, a difference between the client copy of the audio file and the local copy of the audio file.

Abstract: The disclosed embodiments include a system and method for providing communication services that enables a customer to deactivate service when the service is not being used and reactivate the service when the service is being used. This process can save the customer money without the hassle of having to contact a service provider to cancel and reinstall communication services repeatedly. In addition, the customer can maintain consistent service such as, but not limited to, maintaining his/her calling number, maintaining contact information, speed dial information, saved voicemails or recordings, and other user personalized settings.

Abstract: Facilities are provided herein for backing up messages and related activities. An active telephone call is initiated to a voicemail server and recording of the audio stream of the active telephone call is initiated to record a voicemail message being played back during the telephone call. The recorded voicemail message may then be edited, tagged, enhanced, organized with other messages, and shared, as examples. In another aspect, backup of messages is facilitated by an intermediary system that establishes an active telephone call between a voicemail server and a client. The intermediary system passes a request from the client to the voicemail server to commence playback of a voicemail message, and the intermediary system records a portion of the audio stream of the active telephone call.

Abstract: A method and apparatus to process an incoming message is described. The method may comprise, at a recipient system, receiving an incoming message from a message communicator and automatically analyzing message content to identify a keyword included in the message content. Thereafter, a predefined action associated with the keyword may be identified and the action may be performed. In an example embodiment, the predefined action may be a priority with the message, alerting an intended recipient of the message, routing the message to the intended recipient, paging the intended recipient, emailing the message to the intended recipient, sending an SMS message to the intended recipient, or the like. In an example embodiment, a user/owner of a mailbox may search a message database to identify incoming messages which includes the search term in the message content.

Abstract: Interactive voice response mapping used in a transaction between a waiting party and a queuing party includes the queuing party having a queuing calling system (QCS), and communications with the QCS to extract navigational information from the QCS and generating an IVR map. An editor corrects mistakes and removes text that is not relevant to navigational information. Audio communications from the QCS is processed and converted to text or graphical representation. The audio communications from the QCS is compared with an existing IVR map to validate and/or modify the existing IVR map.

Abstract: An interactive voice response (IVR) mapping system (IVRMS) is used in a transaction between a waiting party and a queuing party, wherein the queuing party has a queuing calling system (QCS). The IVRMS communicates with the QCS for extracting navigational information from the QCS and generates an IVR map of the QCS. The IVRMS performs map validation by comparing the IVR map with extracted navigational information, and determines if a certain threshold of matching is not met. Optionally, a primary IVR map and a supplementary IVR map of the QCS are created. An editor corrects mistakes in an automated speech-to-text conversion process, removes text that is not relevant for visual navigation, corrects structure of an IVR map via adding, removes or changes commands, or a combination thereof.

Abstract: Notifying an identified person of a teleconference is provided. Data corresponding to an audio record of the teleconference is received during the teleconference. Pattern recognition is performed on the data during the teleconference. In response to recognizing in the data a pattern corresponding to an identification of the identified person during the teleconference, a device associated with the identified person is contacted during the teleconference. A response related to the audio record is received from the device.

Abstract: The present invention provides a system, method, and apparatus for managing the calling-party identification information offered to called parties. Accordingly, a caller can designate the Caller ID information to the called party based on the context of the call (e.g. the role of the caller) rather than the terminal used. Typically the calling party does this by selecting which of multiple values they wish to have sent with the call request. It is beneficial to implement such a mechanism in a secure manner—the ability to employ a different calling-number or calling-name ID should be restricted to properly-authorized and authenticated persons—in order to ensure the quality of this information. Accordingly, preferred embodiments include an authentication mechanism for verifying the calling party information is authentic.

Abstract: The present invention provides a system, method, and apparatus for managing the calling-party identification information offered to called parties. Accordingly, a caller can designate the Caller ID information to the called party based on the context of the call (e.g. the role of the caller) rather than the terminal used. Typically the calling party does this by selecting which of multiple values they wish to have sent with the call request. It is beneficial to implement such a mechanism in a secure manner—the ability to employ a different calling-number or calling-name ID should be restricted to properly-authorized and authenticated persons—in order to ensure the quality of this information. Accordingly, preferred embodiments include an authentication mechanism for verifying the calling party information is authentic.

Abstract: A method, a system and a device for call processing are disclosed in the embodiments of the present invention. The method includes: obtaining, by a call initiator, address information of all or part of call managers in a network domain that processes a call, where the all or part of the call managers include a call manager that processes the call and is adjacent to the call initiator; sending, by the call initiator, a first call creating request message to an adjacent call manager according to the address information of the all or part of the call managers; and receiving, by the call initiator, a first call creating response message from the adjacent call manager. In the case that a service at a client side is required to be sent through multiple networks at a server side, inter-domain link selection and admission control may be implemented through section call processing.

Abstract: A system for client interaction application integration, comprising a plurality of enterprise communications systems, each comprising at least a call status system; and a callback cloud accessible coupled to the plurality of enterprise communications systems via a data network; wherein, upon receipt of a request from a consumer user to initiate a callback to the consumer user, the callback cloud performs the steps of: (a) obtaining from at least one of the enterprise communications systems a status of communications resources comprising at least an estimated wait time; (b) sending a notification to the consumer user from whom the request was received advising the consumer user of the estimated wait time for service; (c) providing at least an option to wait for a callback to the consumer user from whom the request was received; (d) receiving a selection from the consumer user from whom the request was received; and (e) directing at least one of the enterprise communications systems to initiate a callback to th

Abstract: In one embodiment a method for accessing and interacting with an interactive telecommunications service system is disclosed. The method can include activating a programming mode, entering a plurality of keystrokes to create a keyed sequence where the keyed sequence can include a telephone number and a menu response sequence. The menu response sequence can control the menu driven portion of the telecom service system after the device is connected via a telecommunications network. The keyed sequence can include delays between each of the plurality of keystrokes. The delays can be recorded and a session identifier can also be recorded. The keyed sequence can be associated with the delays and the session identifier in response to the activated programming mode. Access to the service and results from a service request can be automated by the disclosed arrangements.

Abstract: The concept of chained parallel forking is introduced. Addresses of record are included in a contactee's contact resolution preferences to enable an incoming INVITE message to be routed to one or more users as well as other devices, per the contactee's contact resolution preferences. A communication system configured to execute the chained parallel forking contact resolution process is also described.

Abstract: A method, apparatus, and computer program product for generating a social network data structure, the method comprising: receiving a corpus comprising one or more communication indications for one or more customers, each communication indication indicating start time and end time of a communication of the customer; and generating a social network data structure indicating connections between customers based upon the start time and end time indications of communication indication comprised in the communication indications.

Abstract: A crosstalk cancellation device cancels crosstalk noise of at most M disturbing communication lines in a victim communication line forming part of a vectoring group. The crosstalk cancellation device gradually decreases the cancellation depth of a cancelled disturbing communication line in the victim communication line upon a crosstalk noise variation in the vectoring group requiring cancellation of crosstalk noise of a not yet cancelled disturbing communication line in the victim communication line.

Abstract: A packet voice transceiver adapted to reside at a first end of a communication network and to send an ingress communication signal comprising voice packets to, and receive an egress communication signal comprising voice packets from, a second packet voice transceiver residing at a second end of the communication network. The packet voice transceiver includes a far-end echo canceller that reduces echo that is present in the egress communication signal. The far-end communicates with other functional components of the transceiver system and cancels echo or refrains from canceling echo based on the activity of the other functional components.

Abstract: A system for protecting algorithms from side-channel attacks includes a digital processor having a first register, a second register, and a third register; an execution unit; and a processing unit. The execution unit executes an iterative loop for computing a value of a variable and sets a value of the first register based on either an operation or an instruction (or both) within the iterative loop. The processing unit stores the computed value of the variable in the second register and stores a predefined constant in the third register. Side-channel protection may also be provided by a method, a processor, and a program stored on a computer-readable medium.

Abstract: An authentication-encryption unit provides at least one encryption element, where each encryption element encrypts a plain-data block and accordingly generates a cipher-data block. A common checksum is calculated over each cipher-data block. It is possible to select via a selection unit in each encryption element which data bits in each cipher-data block are to be used to calculate the common checksum.

Abstract: The present invention provides a method for establishing a secure communication channel between a client (C) and a remote server (S), said client (C) and remote server (S) exchanging data through an intermediate entity (G), said client (C) having a long-term key pair (skc,pkc), said remote server generating an ephemeral key (sks,pks), the method comprising a mutual authentication step wherein the client (C) sends a public key (pkc) of said long-term key pair (skc, pkc) and the proof that said public key (pkc) is valid to the server (S), and wherein the remote server (S) sends the public key (pks) of said ephemeral key pair (sks,pks) to the client (C). The client (C) generates an ephemeral key pair (skCc,pkCc) and sends the public key (pKcc) of said ephemeral key pair (skcc,pkcc) to the server (S) so as to generate a secret common to the client (C) and to the remote server (S) for opening the secure communication channel.

Abstract: An electronic key registration system includes a controller of a communication subject, an initial electronic key that communicates with the communication subject and has an initial encryption key generation code, an additional electronic key that communicates with the communication subject, and an information center including an additional encryption key. The initial electronic key holds an initial encryption key generated from the initial encryption key generation code and a logic. The controller holds the logic and identification information of the communication subject. The controller acquires the initial encryption key generation code from the initial electronic key, generates an initial encryption key from the initial encryption key generation code and the logic held by the controller, and stores the initial encryption key. The information center sends the additional encryption key to the additional electronic key or the controller through a network.

Abstract: Devices, system, and methods of secure entry and handling of passwords and Personal Identification Numbers (PINs), as well as for secure local storage, secure user authentication, and secure payment via mobile devices and via payment terminals. A mobile electronic device includes: a secure execution environment (SEE) to securely execute code; and a secure video path (SVP) to securely exchange information between the SEE and a touch-screen of the mobile electronic device; wherein the SEE includes a secure password entry module to generate a scrambled on-screen interface, and to send the scrambled on-screen interface to the touch-screen through the SVP.

Abstract: In a data structure of a multimedia file format, a movie box and a media data box are provided. In each box, a non-encrypted size field, a non-encrypted type field and box data field are provided. In box data of the movie box, information data regarding multimedia data is stored. The multimedia data is encrypted and stored in box data of the media data box. The information data is obtained by referring to the container in the movie box. This information data is held as encryption and encoding information data. By referring to the information data, a data unit of the encrypted multimedia data in the media data box is obtained, and the unit data is decrypted.

Abstract: Embodiments relate to methods and systems for gathering, archiving, transmitting, and processing forensic and latent fingerprints. An integrated forensic fingerprint scanning system is provided that includes a number of features for use with forensic-quality fingerprinting. One set of features of embodiments of the portable forensic fingerprint scanning system provides real-time feedback for accurate fingerprinting and training, including visual and/or audio feedback. Another set of features provides cadence-based functionality for improving fingerprinting results. Another set of features provides cryptographic-based approaches to secure highly sensitive collected fingerprint information against loss, theft, or surreptitious modification or tampering. Yet another set of features provides latent fingerprint collections and processing. Still another set of features provides various databasing functions, including centralized storage, data sharing, secure networking, etc.

Abstract: A method for establishing a secure connection between a station and an access point includes transmitting a communications system management message to the station, the communications system management message including an access point nonce. The method also includes receiving a station nonce from the station, and determining a first security key according to the access point nonce and the station nonce. The method further includes securing a connection between the station and the access point using the first security key.

Abstract: An electronic key registration system registers a key ID and an encryption key of an electronic key to a controller installed in a communication subject that communicates with the electronic key through wireless connection. The electronic key includes a monitoring unit that monitors whether or not registration of the electronic key is attempted in a permissible period. A registration invalidation unit prohibits registration of the electronic key to the communication subject when the permissible period expires.

Abstract: There is provided a method and device for determining an inter-channel time difference of a multi-channel audio signal having at least two channels. A determination is made, at a number of consecutive time instances, of inter-channel correlation based on a cross-correlation function involving at least two different channels of the multi-channel audio signal. Each value of the inter-channel correlation is associated with a corresponding value of the inter-channel time difference. An adaptive inter-channel correlation threshold is adaptively determined based on adaptive smoothing of the inter-channel correlation in time. A current value of the inter-channel correlation is then evaluated in relation to the adaptive inter-channel correlation threshold to determine whether the corresponding current value of the inter-channel time difference is relevant. Based on the result of this evaluation, an updated value of the inter-channel time difference is determined.

Abstract: An audio matrix decoder is provided for decoding input signals Lt and Rt into output signals Lout, Cout, Sout, and Rout. The decoder circuit includes a main signal path having a passive matrix decoder and a cross talk canceller configured to apply variable gain values to intermediate signals and to compute the output signals Lout, Cout, Sout, and Rout. The decoder also includes a control signal path having a passive matrix decoder and a linear equation solver. The linear equation solver is configured to compute the variable gain values based on the intermediate signals and the necessary condition that re-encoded values of the output signals Lout, Cout, Sout, and Rout are equal to the input signals Lt and Rt. The linear equation solver is also configured to feed the variable gain values to the cross talk canceller for use in computing the output signals.

Abstract: A system which tracks a social interaction between a plurality of participants, includes a fixed beamformer that is adapted to output a first spatially filtered output and configured to receive a plurality of second spatially filtered outputs from a plurality of steerable beamformers. Each steerable beamformer outputs a respective one of the second spatially filtered outputs associated with a different one of the participants. The system also includes a processor capable of determining a similarity between the first spatially filtered output and each of the second spatially filtered outputs. The processor determines the social interaction between the participants based on the similarity between the first spatially filtered output and each of the second spatially filtered outputs.

Abstract: A method for a user to buy a song from a remote music source, the method comprising the steps of: the user inputting a song melody into an input device connected to the remote music source, wherein the user inputs the song melody using only their mouth; processing the tones of the input song melody so as to determine a set of tonal characteristics associated with the input tones; searching a music database for a song having a like set of tonal characteristics, so as to return at least one candidate song title to the user; playing a sample of the song associated with the at least one candidate song title for the user; permitting the user to purchase the song associated with the at least one candidate song title if desired; and delivering a purchased song to the user via a digital transmission medium.

Abstract: A system for synthesising sounds which allows the user to specify time varying functions for multiple partials. The partials can be cyclical waveforms, for example sine waves, or sampled sounds, or a mixture of each. Partials can be included in the resulting sound by summing, convolution or otherwise. Time varying functions can be specified for the amplitude, frequency or other characteristic of each partial. In some embodiments the resulting waveform can be displayed in various formats to assist with visualising the result of the synthesis.

Abstract: A method for processing audio signals is provided comprising outputting an audio signal; receiving the output audio signal via a first receiving path as a first received audio signal; receiving the output audio signal via a second receiving path as a second received audio signal; determining an echo suppression gain based on the first received audio signal and the second received audio signal; and filtering echo suppression of the audio signal based on the first received audio signal and the echo suppression gain.

Abstract: An audio processing device includes: a directivity adjustment unit adjusting directivity and sharpness thereof in audio picked up by plural microphones picking up audio; and a howling suppression adjustment unit adjusting intensity of suppressing howling of audio picked up by the plural microphones, wherein the directivity adjustment unit adjusts the directivity and sharpness thereof in preference to the howling suppression of audio performed by the howling suppression adjustment unit.

Abstract: A personal audio device, such as a wireless telephone, generates an anti-noise signal from an error microphone signal and injects the anti-noise signal into the speaker or other transducer output to cause cancellation of ambient audio sounds. The error microphone is also provided proximate the speaker to provide an error signal indicative of the effectiveness of the noise cancellation. A secondary path estimating adaptive filter is used to estimate the electro-acoustical path from the noise canceling circuit through the transducer so that source audio can be removed from the error signal. Noise bursts are injected intermittently and the adaptation of the secondary path estimating adaptive filter controlled, so that the secondary path estimate can be maintained irrespective of the presence and amplitude of the source audio.

Abstract: The suppression device for outdoor noises in indoor space solves the technical problems on realizing better sound insulation effect within the room space and creating a quiet atmosphere for people's living environment. The structure includes an anti-noise sound source synchronized to and invert with outdoor noises. The circuit structure of suppression device includes a directional reception and processing circuit for outdoor noises, a attenuation control circuit, a multi-channel digital amplifier circuit, and loudspeaker being installed at the inlet of indoor noises. The directional reception and processing circuit for outdoor noises processes the noise signals collected from the outdoor environment and generates the inverted-phase signals, and then transmits them to the input terminal of attenuation control circuit.

Abstract: Improvements in voice signals transmitted within communication systems are obtained by use of adaptive filters, front and rear microphones, noise cancelling systems and other means and methods. Disclosed embodiments include the use of directional microphones, primary inputs, secondary inputs, adaptive weight generators, canceller outputs to improve signal to noise ratios and other communication attributes.

Abstract: An ear plug system according to various embodiments can include an ear plug device and an electronic control unit. The ear plug device can be configured to include a white noise component, an ear cover, acupuncture nodes and a headband. The white noise component masks select external noises. The ear cover covers a portion of the user's ear. At least one acupuncture nodules is provided in the ear cover to apply pressure, without penetrating the user's skin. The headband extends at least partially around the user's head and applies compressive force to the ear plug device and the acupuncture nodes to ensure a proper fit and comfort. The electronic control unit wirelessly or directly connects to the ear plug device for controlling the operation of the ear plug device.

Abstract: A personal audio device, such as a wireless telephone, includes noise canceling circuit that adaptively generates an anti-noise signal from a reference microphone signal and injects the anti-noise signal into the speaker or other transducer output to cause cancellation of ambient audio sounds. An error microphone may also be provided proximate the speaker to measure the output of the transducer in order to control the adaptation of the anti-noise signal and to estimate an electro-acoustical path from the noise canceling circuit through the transducer. A processing circuit that performs the adaptive noise canceling (ANC) function also detects frequency-dependent characteristics in and/or direction of the ambient sounds and alters adaptation of the noise canceling circuit in response to the detection.

Abstract: A personal audio device, such as a wireless telephone, includes an adaptive noise canceling (ANC) circuit that adaptively generates an anti-noise signal from a reference microphone signal and injects the anti-noise signal into the speaker or other transducer output to cause cancellation of ambient audio sounds. An error microphone is also provided proximate to the speaker to provide an error signal indicative of the effectiveness of the noise cancellation. A secondary path estimating adaptive filter is used to estimate the electro-acoustical path from the noise canceling circuit through the transducer so that source audio can be removed from the error signal. Adaptation of adaptive filters is sequenced so that update of their coefficients does not cause instability or error in the update. A level of the source audio with respect to the ambient audio can be determined to determine whether the system may generate erroneous anti-noise and/or become unstable.

Abstract: An adaptive noise canceling (ANC) circuit adaptively generates an anti-noise signal from a reference microphone signal that is injected into the speaker or other transducer output to cause cancellation of ambient audio sounds. An error microphone proximate the speaker provides an error signal. A secondary path estimating adaptive filter estimates the electro-acoustical path from the noise canceling circuit through the transducer so that source audio can be removed from the error signal. Tones in the source audio, such as remote ringtones, present in downlink audio during initiation of a telephone call, are detected by a tone detector using accumulated tone persistence and non-silence hangover counting, and adaptation of the secondary path estimating adaptive filter is halted to prevent adapting to the tones. Adaptation of the adaptive filters is then sequenced so any disruption of the secondary path adaptive filter response is removed before allowing the anti-noise generating filter to adapt.