Audio scrambler and recorder for cellular telephones
A security device for a cellular telephone includes a cellular telephone interface for coupling the device to the cellular telephone, a microphone, a speaker, and an analog scrambler coupling the microphone and the speaker to the cellular telephone interface. The scrambler is able to scramble voice audio from the speaker and unscramble voice audio from the cellular telephone. The device may further include a radio tuner for providing radio audio to the user through the speaker, and a recorder for recording the voice and the radio audios.
1. A security device for a cellular telephone, comprising:
a cellular telephone interface for coupling the device to the cellular telephone;
a analog scrambler coupling a microphone and a speaker to the cellular telephone interface, the analog scrambler being able to scramble a first voice audio from the speaker and unscramble a second voice audio from the cellular telephone, wherein (1) the first voice audio travels in a transmit path comprising the microphone, the analog scrambler, and the cellular telephone interface, and (2) the second voice audio travels in a receive path comprising the cellular telephone interface, the analog scrambler, and the speaker;
an audio recorder coupled to the transmit path and the receive path for recording and playing back the first and the second voice audios, the audio recorder comprising:
a memory;
a processor comprising:
an input coupled to the transmit path and the receive path between the analog scrambler and the cellular telephone interface for recording the first and the second voice audios in the memory; and
an output coupled to the receive path at the analog scrambler for playing back the first and the second voice audios from the memory.
2. The device of claim 1 , wherein the cellular telephone interface comprises an audio plug.
3. The device of claim 1 , further comprising:
a preamplifier coupled to the microphone;
a compressor coupled between the preamplifier and the analog scrambler, wherein the transmit path comprises the microphone, the preamplifier, the compressor, the analog scrambler, and the cellular telephone interface.
4. The device of claim 3 , further comprising:
a compressor coupled between the cellular telephone interface and the analog scrambler;
a volume controller coupled to the analog scrambler; and
an amplifier coupled between the volume controller and the speaker, wherein the receive path comprises the cellular telephone interface, the compressor, the analog scrambler, the volume controller, the amplifier, and the speaker.
5. The device of claim 1 , further comprising:
an anti-alias filter coupled between the processor and the transmit and the receive paths;
an output filter coupled between the processor and the receive path.
6. The device of claim 1 , further comprising:
a temperature sensor coupled to the processor for detecting ambient temperature.
7. The device of claim 6 , further comprising:
a display coupled to the processor for displaying the ambient temperature.
8. The device of claim 1 , wherein the processor further comprises an alarm clock.
9. The device of claim 1 , further comprising buttons for interfacing a user to the processor.
10. The device of claim 1 , wherein the microphone and the speaker comprise a headset.