| Patent No. | Patent Title: |
| 5268959 | Telephone long distance redialing apparatus and process |
| 5260995 | Electric power circuit for telephone set use |
| 5239579 | Adaptive amplifier circuit |
| 5191606 | Electrical telephone speech network |
| 5182769 | Telephone set having a volatile memory |
| 5172408 | Speakerphone state-controlled alerting arrangement |
| 5164984 | Hands-free telephone assembly |
| 5161184 | Ring-back powered telephone with nonvolatile memory structure |
| 5157721 | Control circuit for an electrical telephone accessory |
| 5151936 | Interface means |
| 5151937 | Adaptive echo canceller |
| 5146494 | Overlapping look-up-and-add echo canceller requiring a smaller me... |
| 5144654 | Automatic telephone dialer system with printed storage |
| 5142655 | Computer input device using an orientation sensor |
| 5136637 | Method and apparatus for automatic redialing of telephone numbers |
| 5133007 | Side tone correction circuit |
| 5128992 | Hybrid circuit |
| 5121425 | Telephone transmission circuit with improved switching device |
| 5113389 | Noise cancellation |
| 5109410 | Two-line, hands-free telephone system |
| 5109409 | Apparatus and method to detect telephony signaling states |
| 5105461 | Telephone line interface circuit |
| 5099512 | Communication terminal device |
| 5097503 | Electronic subscriber line connection circuit |
| 5097502 | Telephone with speed dial and recording of remotely transmitted n... |
| 5095307 | Radio paging communication system |
| 5086462 | Terminal repeater having a function for repeating DC loop signal |
| 5073924 | Telephone line noise filter apparatus |
| 5063593 | Tone-type recognition method |
| 5058153 | Noise mitigation and mode switching in communications terminals s... |
| 5054062 | Circuit for maintaining hybrid cancellation of signals in a ... |
| 5052039 | Line interface circuit |
| 5051981 | Digital filtering |
| 5051980 | Data communication interface device |
| 5042065 | Resetting circuit in a key-telephone system |
| 5042026 | Circuit for cancelling whole or part of a waveform using nonrecur... |
| 5042066 | Dialer circuit |
| 5034977 | Phase accumulation dual tone multiple frequency generator |
| 5033083 | Telephone line switch apparatus |
| 5031212 | Dialer circuit |
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