Help with Science Project -- sound sampler

[vhd987]

I need help designing a simple (seemingly) sound player. I am helping my son with a science project and we need to have the ability to have a person walk up to the display board, select a sound and hear the sound.

My thought is to use some sort of mp3 player, but wanted to keep it simple too. Maybe just a rotary switch....turn it to "sound number 3", press a button and the sound plays. It will have to run off of battery.

I'm fairly electronically illiterate (a thousand apologies), so please be basic in your descriptions.

Thanks a million!

 

[RadioRon]

How long are these sound clips? Less than a second, 2 seconds or ?

 

[vhd987]

Sound clip length

The sound clips will be about 2-5 seconds. The project is about tigers and the sounds are various sounds that tigers make (roar, "purring", etc).

Thanks.

 

[dknguyen]

By keeping it simple, do you mean no microcontrollers or anything? You said you were thinking of using an MP3 player- how much of this project is supposed to be from scratch? Maybe you could hack some yakbacks or something...but that's almost like buying the project (a bit like the MP3 player too), that's why I'm wondering how far you can go on this. You could get a few yakbacks and just take out the circuit board and reroute the buttons to somewhere else...but that's not very project-like.

The only "from scratch" idea that comes to mind for me without a uC (but making sounds is not my specialty) is maybe get an old walkman- the kind that uses solenoids on the buttons so you can apply electrical pulses to activate the functions. Then maybe a bunch of 555 timers, each group dedicated to a sound. Each one might fast forward the tape a set amount of time into the tape, press play, wait for a set amount of time for the sound to play, and then rewind the tape back to the beginning. Huge lag time between playing the sounds and you need to space the sounds out on the tape quite by a few seconds, but it would work...maybe. And maybe add in some extra time to account for the maximum rewind time, and the delay that comes from actuating the buttons and other things like that...

 

[stevez]

I seem to recall Radio Shack, among others, selling a voice record/playback IC that was pretty simple. I also recall an amateur radio project that uses a similar IC to record/playback - so someone worked out all the details. A search of ARRL archives is likely to turn something up. IM me and I'll help with that if you like.

 

[vhd987]

What's a Yackback?

Sorry for the ignorance, but what is a yackback?

Thanks.

 

[dknguyen]

It was a little toy that you push a record button, say something into it up to 20 seconds long or so. Two playback buttons play back the sound either forwards or backwards.

 

[Blueteeth]

Hi,

Usually (almost always) I'd recommend a wonderfully complex DIY approach. But getting audio quality up to spec, better than crappy 8bit 8khz (phone quality?) I'd say go for a cheap MP3 player. They're so cheap now days, sure you won't have your rotary switch, but they go for about 15UKP for a small one these days, and most have recording capability.

Failing that, there are ASIC's that will do that job, some have built in memory, others will require external. The sound quality is pretty weak IMO, but it'll be a whole lot easier than programming a micro with ram, flash, and a ADC/DAC.
Obviously if you use a small speaker, then sound quality won't really need to be good, because a small speaker would have a limited frequency response.

So, the mp3 player idea aside...a nice kit that will handle the audio and storage, and maybe add your own simple switching mechanism, be it with a rotary switch, simple logic, or a microcontorller.

some links:
**broken link removed**
**broken link removed**

The Jaycar one looks great, the chip it uses allows multiple messages to be accessed seperately - may require modification of the kit, but should work quite well. Plus its cheap $40 AUS... dunno what the exchange rate is though

There are some ISD chips like the ISD2540 which would do what you want. But the above kits would work out (especially the 2nd). All you would need is a rotary switch, as you suggested and a button.

Good luck,

Blueteeth

 

[RadioRon]

I was wondering if this could be done using one of those music keyboards that can also sample external audio and then play those sampled clips back. The ones that I have seen take only very short samples, and the individual keys don't select different samples, they only change the tone of the selected sample. So, not much help there I guess.