Sound chip query

[steve1]

Our granddaughters have several toys that have what I assume to be sound chips in them.  One of them is a fire engine with four individual sounds, motor and wheelspin noises, sirens, a very convincing (non-robotic) voice and music. There are also those (annoying) greetings cards containing similar.

 

Given these toys are relatively cheap (and the cards cheaper) I was wondering:

 

a. Why can't these be re-programmed with 'loco' sounds?

 

b. How come they are so cheap but loco sound chips are so expensive?

 

steve

[RobjUK]

The simple sound chips in cards and some toys generally have a fraction the data storage and no CPU, just enough logic to send some part of the stored data to a DAC which feeds the audio output.

 

They cannot play multiple sounds simultaneously or manipulate the sounds in any way.

 

A loco sound unit has a rather powerful CPU, lots of data storage and enough processing power to change the sounds on the flu, as well as mixing two or more simultaneously. 

 

You can get a greeting card type IC in a conventional package to build in to your own stuff, complete with a demo PCB for control and connections, for a pound or so; eg.

https://www.ebay.co.uk/p/Isd1820-Voice-Recording-and-Playback-Module-With-Mic/1388908318?iid=181925204925&chn=ps

 

That particular one has a maximum recording  / playback time of 20 seconds in "voice quality".

 

If you compare that to a minimal tape recorder type device, a loco sound chip is more like a music synthesiser for overall complexity; eg. near something like this: 

https://en.wikipedia.org/wiki/Roland_Sound_Canvas

 

In fact, considering they have been out 20 years, the CPU in eg. a loksound 5 is probably rather more powerful!

 

 

Edited May 4, 2019 by RobjUK
typo