Work out which memory you actually exhausted
The error text usually tells you. A message naming CUDA or a device means the graphics card's memory filled up, and the amount your card has is fixed and cannot be extended. A plain out of memory or a process killed without explanation generally means system RAM, which is affected by everything else you have open.
This distinction decides the fix. Closing browser tabs frees system RAM and does nothing at all for graphics card memory. Switching to processor-only mode moves the problem from one to the other, which helps if your RAM is generous and your card is small.
The fixes, cheapest first
Use a smaller model, which cuts memory roughly in proportion to size and is the single most reliable fix. Then try a quantised version, which stores the model at lower precision and can halve the requirement for a modest accuracy cost. Long files can also be split into shorter pieces, since some setups hold more of the audio in memory than you would expect.
If none of that leaves you with a model accurate enough for your audio, you have hit a genuine hardware ceiling rather than a solvable configuration problem. At that point the choice is buying more capable hardware or sending the file somewhere that already has it, and a free first file here will tell you whether the larger-model output is even worth the trouble.
Frequently asked questions
Will closing other programs solve it?
Only when it is system RAM that ran out. If the error names CUDA or your graphics device, that memory is fixed in size and closing applications will not release any of it.
Does splitting the audio into pieces help?
Sometimes. It reduces what is held in memory during processing on some setups, though the model itself is usually the larger consumer. Try a smaller model first, since that is more reliably effective.
How much memory does the largest model need?
More than most consumer graphics cards carry, which is why this error is so common with it. A quantised version of a mid-sized model is the usual compromise between what fits and what is accurate.