MacBook SSD replacement — sudden motion shock sensor in optical bay?
This solution may not directly answer your question, but it may be relevant: I would advise you against putting your HDD in the optical bay.

I tried that. Putting the SSD in place of the HDD, and moving the HDD in the optical bay, which is just under the keyboard… And I got to hear the noise of the HDD spinning and the noise the heads when accessing cylinders… Bad idea. After a few hours, I switched HDD and SSD.

So, I would recommend you to leave the HDD in its bay and to put the SSD in the optical bay. That way your question is solved, and you don't get to hear the HDD working.
And if you notice an extra delay when booting, just select the SSD (which is in the optical bay) as booting drive in the system preferences. You will need to enter your password twice, once and for all. Then, your mac will immediately find the SSD when starting up.