Record-Delay-Play sound-bytes

[jimandy]

I am looking for a kit or assembled device that would delay playback of an audio input signal for approximately 10 seconds. Quality is not important.

Alternatively, a device that would record approximately 10 seconds when triggered and play back immediately after, then reset to repeat the process.

In either case the "sound-bytes" would be +- 10 seconds with long intervals of silence between.
Suggestions?

[fripster]

hi. you can get a kit at SparkFun that does just that on a hardware trigger.

just my two cents.

Fripster

[jimandy]

Thanks Fripster,

Of all the places I should have looked at first, I found pretty much what I can use at Radio Shack. The module records 20 seconds of audio, pushbutton controlled - about ten bucks.

I would prefer an audio delay solution, much like broadcasters use to avoid embarrassing moments during live broadcasts but they cost way too much. I did find a simple audio delay circuit in EDN (1 comparator, 1 D-flop and a shift register) but for the desired 10 second delay the shift register would have to be megabits long.

[fripster]

Is usage of a small single board computer (SBC) with audio on-baord a possible solution? Then it would be a software-only solution. Drawback is that it is a bit expensive. Making software with a ringbuffer for audio is not so very difficult. An ethernut board could be a solution maybe?

fripster

[jimandy]

Making software with a ringbuffer for audio is not so very difficult

It would be for me, Fripster. I'm getting too old to think and would prefer an off-the-shelf solution. Seems like it would be a neat project for a N & V article.

Thanks anyway.

[haklesup]

Well, Given there are a few off the shelf solutions that require you to press a button to record and toggle another button to play back (for instance a talking greeting card, talking picture frame, that RS gadget, many baby toys). You could add some circuitry to trigger the events.

I'm not too clear on what you mean by when triggered but lets consider a simple case

You wire a 555 timer to reset when you let go of the record button and then close the play button 10 seconds later. To be more specific I would need more details about what triggers it, if the recorder requires normally open or closed buttons etc. An NPN transistor can probably take the place of the button.

A couple 555 timers (or a 7555) could alternate between record and play and maybe even use an op amp and mic to detect noise to set the thing in motion.

You need to make some timing diagrams I think to proceed. Something in the seconds scale like
noise made, record enabled for 10 seconds, playback enabled for 10 seconds, stop and wait for loud noise again.

[jimandy]

Thanks Hacklesup.

Here'r the bigger picture. I have posted another topic regarding filtering junk phone calls. Although not a perfect solution - the JF Teck with ring control does almost everything I want. One drawback is that it does not pass CID info to the house phones. My idea is to have a voicing CID (VCID) unit connected to the delay device. This unit "speaks" the CID info and is useful for people with sight impairment. The audio is then recorded on a digital audio recorder (DAR) and plays it back via a speaker located in the room where my house phone is located. I have purchased the Radio Shack 20 second recorder and found that it has a press & hold to record switch and a pulse to playback switch. I already have a VOX module from an earlier project so my plan it to connect both the VOX and DAR to the output of the VCID. The VOX will provide an "on" signal for the DAR and it will record as long as the audio CID is present and then a pulse-on-trailing-edge circuit will play back the digital recording. The trick will be to pass this audio to the remote (in the house) speaker *only* when a ring-through occurs - that is when a call is accepted by the JF Teck as one coming from a number on my approved caller list.