The report, cited in Fortune, found that Siri only understood 83 per cent of queries in noisy conditions and 89 per cent in a quiet room. Perhaps worse, Siri only answered accurately 62 per cent of the time in a street and 68 per cent in a quiet room.
By contrast Google understood 100 per cent of the questions and replied accurately 86 per cent of the time. Overall, Siri received an accuracy grade of D and Google a B+.
In conclusion, Munster wrote that Siri simply didn't stack up against Google and was therefore not ready to be a viable mobile search alternative.
By Munster's estimation, Siri lags about two years behind Google but expects Siri to "improve meaningfully" with the release of iOS 6.
For advertisers, this could mean a delay in tapping into the potential of voice-activated search, whether via search engine marketing or through voice-activated coupons.