If you want to hide the survey title on the welcome page of your survey, you can create a custom template in the Template editor. 

1. Go to the Template editor under Configuration on the top menu bar in the Dashboard.

2. Let's assume you are using the survey template called "default".  You can't edit a core template, so click copy to create a copy and give it a unique name.

3. Next, set the Screen to "Welcome page" (top right), and then select the Screen part file "welcome.pstpl" and then on line #10 -- delete :

<h1>{SURVEYNAME}</h1><br />

4. Then go to your survey, and set the default template to the one you just created.

Here's a screen shot of the important elements: