If you are reading a sentence in quotes ("SENTENCES WORDS"), NVDA will ignore the quotation mark on the right.
The problem is that if there is any symbol next to the quotation mark on the right, NVDA will consider the quotation mark on the right. For example "hello."
Now if we remove the fullstop from the example, we will only hear quote once.

A note:

I don't know if this problem is caused by Espeak. NVDA may be sending the wrong data for Turkish to Espeak.
Repeat the same steps for English and everything seems correct.
Since I don't know how to analyze this process more deeply, I wanted to create an issue. I will close this issue with your referrals and recreate it in Espeak-NG repo.
I don't know how to repeat these steps for Espeak. I can ask these questions, but I can also listen to your thoughts and suggestions.

And if this problem is in NVDA codebase I want to submit a pr. Could you please tell me which files I can analyze?
I want to make a small improvement. I love the open source world and NVDA is a great project.

Thanks for reading the note.

Steps to reproduce:

1. Change Punctuation/symbol level: most

2. Change Synthesizer: EspeakNG

3. Change synthesizer language: Turkish

4. Typing
   "Merhaba dostum" dedi.
   Or coding example:
   functionCallProduce("a string")

5. Scroll through the text with the up and down arrows.

Actual behavior:

In both examples, you will hear the quotation mark only 1.

So:
tırnak Merhaba dostum dedi.

Or:
functionCallProduce açparantez tırnak a string kapaparantez

Expected behavior:

The following output should be voiced:
tırnak Merhaba dostum tırnak dedi.

Code example:
functionCallProduce açparantez tırnak a string tırnak kapaparantez

System configuration

NVDA installed/portable/running from source:

Tested installed, portable

NVDA version:

2020.4

Windows version:

Windows 10, 64 bit

Name and version of other software in use when reproducing the issue:

Other information about your system:

Other questions

Does the issue still occur after restarting your computer?

Yes

Have you tried any other versions of NVDA? If so, please report their behaviors.

If add-ons are disabled, is your problem still occurring?

yes

Does the issue still occur after you run the COM Registration Fixing Tool in NVDA's tools menu?