Apple's Head of Search Vipul Ved Prakash and Tom Gruber, Head of Siri's Advanced Development Group, have quit the company which is currently reshuffling its Siri team.
According to a report in The Information on Thursday, Apple has confirmed both the departures.
One of the original Siri co-founders, Gruber "will be pursuing personal interests in photography and ocean conservation".
Prakash joined Apple in 2013 after Apple acquired the search engine and analytics firm Topsy where he served as a CEO.
"The deal was valued at upwards of $224 million. Apple shut down Topsy two years after its acquisition," reports 9to5mac.com.
Revealing its future plans, Apple last week formally announced to make ex-Google executive John Giannandrea its Chief of Machine Learning (ML) and Artificial Intelligence (AI) Strategy.
Reporting to CEO Tim Cook, Giannandrea who joined Apple in April will be in charge of Apple's ML division, Siri and the Core ML team.
Giannandrea will look after further development of Core ML and Siri technologies.
According to media reports, Apple lags behind from Google and Amazon in key AI areas like Natural Language Processing (NLP) and computer vision needed to power voice assistant features in Siri.
Apple has invested in Siri and HomeKit to compete with Google Home and Alexa-based smart home systems.
In 2017, Apple added an AI chip called Neural Engine to the A11 Bionic for the iPhone 8, iPhone 8 Plus and iPhone X to work with the Image Signal Processor (ISP).
