Those of us who use speech recognition are giving our computers a pretty good workout — the speech engine takes a lot of compute power. As long as you have a fairly powerful computer and do a couple minutes of maintenance every few weeks you’ll be all set.

Unless, like last week, it’s very hot, and you try to use your computer in a room that’s not air-conditioned.

Computers naturally get warmer when you use them. On a cool day the heat dissipates pretty well by itself. Last week was a different story, however. When a computer gets too hot, the computer fan kicks on to cool it down. If it’s still too hot the chip will automatically slow down. This all presents problems for the speech user. First, the excess noise of the fan can make it harder for the microphone to process your speech, and can make the signal that ultimately passes to the computer chip less clean so the computer has to work harder to decipher it. These can both increase the lag between you saying a command and the computer recognizing it. And if the chip slows down, processing slows down further.

The moral of the story is if you find yourself trying to use speech on a hot day and you think the computer is slowing down, it probably is. Turn it off for little while and it will do better when you turn a back on. Find air-conditioning or wait till the air temperature is cooler and it will do even better. And make it a habit to turn off your computer when you’re not using it so it can cool down completely.

FYI Here’s advice on the ideal setup for speech-recognition and a two-step maintenance program for speech-recognition.