Telephonic communications – Including aid for handicapped user
Reexamination Certificate
2001-07-24
2003-04-01
Ramakrishnaiah, Melur (Department: 2643)
Telephonic communications
Including aid for handicapped user
C379S088140, C379S093170
Reexamination Certificate
active
06542582
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates to filtering signals and, more particularly, to filtering signals in a conference call environment.
BACKGROUND OF THE INVENTION
A conventional telecommunication device for the deaf/teletype (TDD/TTY) enables people who are hard of hearing or deaf to communicate with other parties via standard telephone lines. For example, one way in which a deaf party may communicate with another party is if both parties use a TDD. In this case, a calling party may type using a standard keyboard included with the TDD and the called party reads the message on a display associated with his/her TDD. The called party may similarly type a message using his/her TDD and the calling party may read the message using his/her display.
A second way in which a hearing-impaired/deaf person may communicate via standard telephone lines is referred to as voice carry over (VCO). In this case, a conference call is established between a first party, a communication assistant (CA) (also referred to as a conference administrator) and a second party. The first party may be a deaf person who has a TDD/TTY and the second party may be a person with normal hearing who does not have a TDD/TTY device.
When the deaf party wishes to make a call, he/she dials a telephone number for the CA and tells the CA the telephone number to which he/she would like to be connected. The CA may dial the number and provide a greeting to the hearing party. When the hearing party speaks, the CA types what is slid and the deaf party reads the text using the TDD/TTY's display. The deaf party may respond to the message on the display by speaking to the hearing party, whereby the deaf party's voice is transmitted to the hearing party in a normal manner. In this manner, the deaf party may communicate with hearing and hearing-impaired parties using conventional telephone lines and conventional TDD/TTY equipment.
In the second scenario described above (i.e., VCO mode), a conference bridge is established to enable the three parties (the hearing-impaired party, the CA and the hearing party) to communicate. The hearing-impaired party's TDD/TTY includes a conventional modem for receiving the text messages from the CA. When the CA begins to type and the text data is transmitted to the TDD/TTY, the TDD/TTY modem responds with a synchronization (sync) tone. In typical systems, this sync tone is transmitted at a very high decibel level and is received at the conference bridge. As a result, both the CA and the hearing party receive the high decibel sync tone. This sync tone is extremely bothersome and even painful for the CA and the hearing party. Other annoying tones may also be transmitted from TDD/TTY echo path to the CA and the hearing party.
To combat the annoying sync tone and other tones from being transmitted to the CA and the hearing party, some systems terminate the receive leg of the connection from the conference bridge to the TDD/TTY each time the CA types. That is, the system breaks the receive connection between the conference bridge and the TDD/TTY to prevent signals from the TDD/TTY modem from reaching the conference bridge. In this case, the connection between the CA and the TDD/TTY modem remains in place so that the TDD/TTY can receive the text message from the CA. There are, however, several drawbacks with this approach.
For example, one drawback with this approach is that the automatic gain control (AGC) of the conference bridge goes into spasm when the connection is frequently broken and then re-established. That is, the conference bridge may first over-amplify and then over-attenuate the receive leg of the connection from the conference bridge to the hearing-impaired party when the connection is re-established. In addition, a loud pop often occurs on the conference bridge caused by the re-synchronization of the pulse coded modulated (PCM) data streams between the CA's modem and the TDD/TTY's modem.
Another drawback with terminating and re-connecting the connection from the TDD/TTY to the conference bridge is that the first word or words spoken by the hearing-impaired party when he/she responds to the CA?s text message is often clipped. That is, the hearing-impaired party's first word(s) are often not transmitted to the hearing party because the connection to the conference bridge is not re-established before the non-hearing party begins to speak.
SUMMARY OF THE INVENTION
There exists a need for a method and apparatus that improve problems associated with a conference call involving a TDD/TTY.
These and other needs are met by the present invention, where signals from a TDD/TTY device are filtered during a conference call. By selectively filtering transmissions from the TTD/TTY, the annoying/painful tones associated with a TDD modem are not transmitted to the CA and the hearing party.
According to one aspect of the invention, a method for providing telephone services for the hearing-impaired is provided. The method includes establishing a conference call between a hearing-impaired party, a hearing party and a communication assistant. The method also includes sending a voice message from the hearing party to the communication assistant, generating a text message by the communication assistant, the text message corresponding to the voice message and transmitting the text message. The method further includes receiving the text message by the hearing-impaired party using a device that includes a modem, the modem outputting a synchronization tone in response to receiving the text message. The method also includes filtering the synchronization tone so that the synchronization tone does not reach the communication assistant and the hearing party.
Another aspect of the present invention provides a computer-readable medium that includes stored sequences of instructions that are executed by a processor. The instructions cause the processor to allocate resources for maintaining a conference call between a hearing-impaired party, a hearing party and a communication assistant and pass a voice message generated by the hearing party to the communication assistant. The instructions also cause the processor to forward a text message generated by the communication assistant to the hearing-impaired party and receive a synchronization tone from a modem associated with the hearing-impaired party. The instructions further cause the processor to filter the synchronization tone so that the synchronization tone does not reach the communication assistant and the hearing party.
According to a further aspect of the invention, a device for facilitating communications with a hearing-impaired party is provided. The device includes a modem, a processing device coupled to the modem and a display. The modem is configured to receive data and the processing device processes the received data and outputs text data. The display receives the text data from the processing device and displays a message to the hearing-impaired party. The processing device is also configured to block data transmissions from the modem. having at least one predetermined frequency from being transmitted to another party.
Other features and advantages of the present invention will become readily apparent to those skilled in this art from the following detailed description. The embodiments shown and described provide illustration of the best mode contemplated for carrying out the invention. The invention is capable of modifications in various obvious respects, all without departing from the invention. Accordingly, the drawings are to be regarded as illustrative in nature, and not as restrictive.
REFERENCES:
patent: 6307921 (2001-10-01), Engelke et al.
patent: 409149186 (1997-06-01), None
Ramakrishnaiah Melur
WorldCom, Inc.
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