After viewability here is audibility

After its viewability standards, widely accepted by the profession, the Media Rating Council (MRC) is publishing the audibility requirements for advertising and editorial content, audio streaming and progressive-download on any Internet connected device (but not on AM/FM over-the-air digital broadcasts). Audits and accreditations of measurers will follow the establishment of these audio measurement standards. MRC validations help advertisers to choose their advertising media and decide on which metrics to base planning, monetization and invoicing.

Definition 1. What is an “Audio Ad Impression”?  

• The ad must be played with a digital audio player "in an unmuted state and at a nonzero volume" (whether browser or in-application environment).
• The ad must be filtered for Invalid Traffic Detection and Filtration (following MRC Guidelines) ; Sophisticated Invalid Traffic Detection is strongly encouraged and is required for audience metrics.

Definition 2. What is an "Audible Ad Impression"? 

• Like a Viewable Ad Impression, an Audible Ad Impression must play for a minimum duration of two continuous seconds to be measured.
• Measurements must occur on the client side, not on the server side (log file analysis).
• The ad must be loaded and initiated by the user ("insofar as possible"); what about autoplay?

Questions

• The new standards will certainly be applied in European and Asian markets. Nevertheless, besides global advertising groups, companies or associations involved in establishing the standards are mostly American: Radio Advertising Bureau (RAB), National Association of Broadcaster (NAB), Interactive Advertising Bureau (IAB), 4As and ANA. Is the all American MRC becoming de facto a world-wide organization?
• Duration: two seconds ; only two seconds? Is that enough to define an "Audible Ad Impression"? Especially if "any part of the ad qualifies", as specified by the MRC. Further research is needed. In the mean time, why not let each advertiser decide which duration is best.
• How to manage compatibility of all audio measurements, whether legacy terrestrial radio (broadcast) or streaming. How to combine the two measurements in order to calculate one single and hybrid GRP (Reach and Frequency)?
• How long will the validation of measurement techniques take ("accreditations")? How expensive will they be? Will viewability specialists be the first audited and accredited for audibility? When it comes to video, how will measurers combine - or separate - viewability and audibility?