Audio waveform for digital recording

Claim 2

Apparatus for combining subaudible and audible tones for storage of bits of digital information on an audio track, comprising, first means for generating a subaudible tone burst of a predetermined duration for recording on said audio track, second means for logically representing said bits of digital information for storage on said audio track following said subaudible tone burst, third means including a multiple frequency oscillator circuit means operatively connected to said second means for responding to a first output condition of said second means by generating an audible tone code pattern comprised of spaced apart tone bursts indicative of said bits of digital information for storage on said audio track, and responding to a second output condition of said second means by generating audible tone bursts of a second frequency to serve as spaces between said spaced apart tone bursts.

Claim 3

Apparatus as claimed in claim 1 further including fifth means for providing a relatively uninterrupted, continuous transition between the audible tone bursts of the different frequencies.

Claim 4

Audio reproduction apparatus, comprising, a multitrack storage media having a plurality of segments of audio information recorded on one or more tracks and including tone code patterns associated with said segments of audio information, each tone code pattern consisting of a subaudible tone followed by an audible tone code pattern corresponding to bits of digital information, said audible tone code pattern identifying the location of the subsequent audio information to be reproduced, first means operatively connected to said multitrack storage media for presenting said audio information to a listener, second means responding to said subaudible tone to deactivate said first means prior to reproduction of said audible tone code pattern, third means responding to said audible tone code pattern to cause reproduction of audio information at a track location defined by the digital information content of said audible tone code pattern, and fourth means responding to the conclusion of said audible tone code pattern by activating said first means prior to reproduction of the audio information.

Claim 5

Audio reproduction apparatus, comprising, a multitrack storage media having a plurality of segments of audio information recorded on one or more tracks and including tone code patterns associated with said segments of audio information, each tone code pattern consisting of a subaudible tone followed by an audible tone code pattern corresponding to bits of digital information, said audible tone code pattern identifying the location of the subsequent audio information to be reproduced, first means operatively connected to said multitrack storage media for presenting said audio information to a listener, second means responding to said subaudible tone to deactivate said first means prior to reproduction of said audible tone code pattern, third means responding to said audible tone code pattern to cause reproduction of audio information at a track location defined by the digital information content of said audible tone code pattern, and fourth means responding to the conclusion of said audible tone code pattern by activating said first means prior to reproduction of the audio information.

Claim 6

Apparatus as claimed in claim 3 wherein said audible tone code pattern is comprised of discrete audible tone bursts.

Claim 7

Apparatus as claimed in claim 3 wherein said audible tone code pattern is comprised of spaced apart audible tone bursts.

Claim 8

Apparatus as claimed in claim 5 wherein each tone burst corresponds to a bit of digital information and the length of each tone burst is indicative of the state of said bit.

Claim 9

Apparatus as claimed in claim 3, wherein said audible tone code pattern is comprised of alternate first and second tone bursts of a first and second frequency, respectively, thelength of said first tone bursts being indicative of the state of the bits of digital information, said second tone burst providing spacing between each bit of digital information.

Claim 10

Apparatus as claimed in claim 7, wherein first tone bursts of a first predetermined length correspond to a logic 1 and first tone bursts of a second predetermined length correspond to a logic 0.

Claim 11

Apparatus as claimed in claim 7, wherein the initial and final tone code bursts of said audible tone code pattern is a second tone burst of a duration longer than the remaining second tone bursts comprising said audible tone code pattern, said remaining second tone bursts being substantially identical.

Claim 12

Apparatus as claimed in claim 7, wherein the frequency of said key tone is approximately 40 Hz, the frequency of said first tone bursts is approximately 3 kHz, and the frequency of said second tone bursts is approximately 2 KHz.