How to adjust the speed of of the text to speech when in the secure browser on an iPad.
Step 1: Pause and close the test app.
Step 2: Go to Settings > Accessibility.
Step 3: Turn on Speak Selection, and set the speed to something comfortable
Alternately, when you are in the test, do not use the "Speak Question" option that is embedded into the test. Instead, tap/hold then highlight the text you want, and the usual iOS menu bar pops up - tap Speak.
This may be solved when the next version of the Secure Browser is installed for testing during the 2015-16 school year.