All the incentives are aligned: advertisers want to connect with customers and customers are typing search terms, hunting for the phone number of web site of the radio ad they just heard. What was that special deal they said to mention? Where can I hear the ad again?
Google should open “ad search” and let advertisers submit audio, video, transcriptions, and links along with optional metadata like format, media outlets, etc.
Then search could handle things like ‘radio ad’, ‘tv commercial’, etc.
The advertisers do the work of populating the content and everybody wins.