Is there a way to silence all sound that comes from my iPhone but allow a particular person to contact me and make a sound on iPhone?

I suggest to take a look at this support guide:

Use Do Not Disturb on your iPhone, iPad, and iPod touch - Apple Support

Regards

Giulio

Go to the contacts and click edit on the person you want to give special access to. In the older versions of ios you can add the contact to your favorites list and they will still be able to call you when your phone is in Do Not Disturb Mode. In more recent ios version you have the option to allow a contact to your favorites for both phone calls as well as texts. There is another option in more recent ios versions when editing contacts that allows someone to still call and/or text you even when your phone is on silent - go to contact, click on edit, click on ringtone for phone calls and turn on Emergency Bypass to allow this person to call you even when your phone is on silent and/or Do Not Disturb Mode without adding them to your favorites. You can enable the same feature for text messages by clicking on ringtone for texts and turning on Emergency Bypass. **Warning, once Emergency Bypass is turned on for a contact you will not be able to silence their calls/texts without either turning the volume all the way down on your phone or by going back into contact settings and turning off Emergency Bypass**