This is just a quick tip for psychologists who want a silent or beepless stopwatch, as they are very easy to make.
Stopwatches are often used when psychologists do neuropsychological assessments as they involve the timing of participant responses. Beeps can sometimes be distracting, especially to people who may have brain injury or might be emotionally disturbed, so many assessments recommend stop watches that don’t beep every time you press a button.
Surprisingly, few actually have this option and I keep seeing online discussions about where to get a silent stopwatch. It’s no coincidence that one of the few that allows you to switch off the beep is most commonly sold with books about psychological assessment.
However, you can make virtually any stopwatch silent very easily. If you unscrew the back – you may need a smaller ‘watchmakers’ or ‘jeweller’s screwdriver’ like this one – on the back plate you can see the the piezoelectric speaker (the circular metal disc – on the left in the image). Just cover it with tape and voila! you have a silent stopwatch.
Cheaper than commercially available devices with silent options and works with every stopwatch I’ve found so far.
Mind Hacks 
I had to cut two wires that were connected to my speaker. Thanks for the suggestion, just saved me money and as a graduate student in psychology that is very helpful!
You can also use your phone’s stopwatch. Most modern phones will have a stopwatch function and you can put them into silent mode VERY easily.
I am a film maker and thid little trick saved the day for me.
Thanks for posting this.
No beeps in my film now. LOL (=
I am a script supervisor, also in the film industry. When rolling sound, it is necessary for everything to be as quiet as possible, even my stopwatch. This trick will save me lots of money and time at the jewelers. Thank you vaughanbell.
Brilliant. Now all I need is to find a tiny screwdriver…which we surprisingly don’t keep as standard in the Psychology department!
You are a lifesaver! I ended up using glasses screwdriver which worked brilliantly.
Great advice! You saved me from having to return a stopwatch with a very loud beep and to try to find another. Small snag — when I opened up the stopwatch, I turned it upside down and three small black pieces of plastic and a tiny spring fell out. Took a while but eventually managed to get them back where they belonged. Thanks!
This is a wonderful hack! I need a silent timer for my licensure exam (Interior Design) and am so glad you shared this, I didn’t even have to ruin my watch, take the tape off and it’s back to normal! 🙂