Which type of traffic may be blocked after installing Cisco ASA 5500 series firewall in transparent mode in VOIP Network?

All except G711 & H323 so u have to add exceptions for other ports and protocols manually

by default all incoming traffic is blocked on any vendor firwall if you want to make communication then which services you want that service protcol is  allowed exmaple you want voip allowed sip h323 prtocol traffic

Traffic from untrusted interface is blocked

all network layer traffic will be blocked unless you allow it with an extended access list. ARP traffic is allowed through the transparent firewall without an access list