Iolts, You Could Make Mistakes on the Speaking Exam

Pronunciation score goes down on speaking. Listening score goes down because you are writing the word incorrectly, right? And if we think about other pronunciation issues that are not grammar related, there are so many minimal pairs with t h and s or t h and write. So for example, ting and sing, think and sink. If you cannot say the t h correctly, you won't hear it correctly. I ain't going to let it go, am i?