Uncannily, youtube suggested this video for me to watch.
The instrument here is a an Istanbul Clap Stack.
Thank you youtube!
music.stackexchange.com/users/9426/Brian THOMAS
Not sure what you mean by "ensemble" hand claps, though there are a few ways drummers have tried to emulate electronic clap sounds.
Basically, they boil down to various rim-flam techniques .
You can experiment and adapt whatever sorts of drums you have available.
music.stackexchange.com/users/31335/Sarkreth
I wanted such an instrument to cover some pop songs tomorrow, e.g. Macklemore's "Thrift Shop" at 00:30:
I also couldn't find anything I could easily buy at a music store, so I experimented with household items.
I imagined maybe a folding paper or plastic fan might work, but I didn't have one.
But I found you can get pretty close with half a deck of cards.
Hold the half-deck in one hand and use the other hand's thumb to do a controlled snap on the short side, like a flip book but really fast.
It's easy to improve technique by playing around with it.
I've found that if you hold the deck in a shape like, um... remember those old-school rubber erasers?
If you make your deck look like that, you add on more choral "voices" (separation between claps), and sounds even more like an ensemble clap.
Of course, not loud enough by itself
but I plan to hold it near a microphone.
music.stackexchange.com/users/6041/Andrew Cheong
I don't think I've encountered an acoustic instrument as a percussionist that perfectly emulates a hand clap sound.
Typically you could use something like a small whip (two boards hinged together), or large castanets to provide a similar effect.
SONOR apparently makes a 'hand clap box' that is supposed to sound like hand clapping and would be playable by a single musician
(Although personally I think it sounds too close to a woodblock): http://www.sonor.com/instruments/percussion/hand-percussion-add-ons/hand-clap-block/
music.stackexchange.com/users/43119/John Stark
There was an acoustic clapping device that was a metal rod and it had plastic or hard rubber discs that you slid down to create the clap sound.
Haven't seen it in years......
music.stackexchange.com/users/58914/TImothy Strelau
Though you do specifically ask for acoustic percussion instruments, I'll answer off topic that, in terms of faithfully simulating a sound, an electronic sample would be very effective and there are hardware form factors that would work nicely in a live, acoustic group setting: pad or button to trigger, built-in speaker, etc.
music.stackexchange.com/users/43889/Die Hard
When there's a group of musicians playing, it's often not practical for several of them to stop what they're doing so they can clap instead, so is there an  acoustic  percussion instrument that can be played by one person, that sounds like ensemble handclaps, i.e a group of people clapping together?
What acoustic percussion instrument sounds like handclaps?
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music.stackexchange.com/questions/60654
music.stackexchange.com/users/9426/Brian THOMAS
An electronic sample would be very effective in simulating a sound and there are hardware form factors that would work nicely in a live, acoustic group setting: pad or button to trigger, built-in speaker, etc. There are hardware form factors that would work nicely in a live, acoustic group setting.
In terms of faithfully simulating a sound, an electronic sample would be very effective. There are hardware form factors that would work nicely in a live, acoustic group setting.