Amazon’s $200 million Alexa Fund for the promotion of voice-powered products and conversational computing today announced investment in new early-stage startups Bamboo Learning, Endel, and Aiva.

Bamboo Learning is exploring ways to teach people using voice-based devices like Echo speakers. The Bamboo Music Alexa skill teaches people the fundamentals necessary to play an instrument and increases the difficulty level as users advance and learn more. Bamboo was founded by former Amazon Devices VP Ian Freed.

Aiva is a health care assistant that combines a smartphone app with voice commands to help caretakers respond to calls for care. Aiva took part in the 2017 Cedar-Sinai accelerator for health care companies.

Endel is a graduate of the Techstars Music Accelerator and according to its website makes “personalized sound environments” to help people focus, relax, sleep, or get moving.

Financial terms of the deals were not disclosed.

Each of the companies will participate in October 9 presentations at Demo Night for the second cohort of the Alexa Accelerator, a startup accelerator paid for by the Alexa Fund and hosted by Techstars.

The news comes days after the Alexa Fund participated in a $6.7 million round for prefabricated home startup Plant Prefab, and a week after Amazon debuted nearly a dozen new devices, including second-generation versions of the Echo Dot and Echo Show, as well as the Echo Auto and a series of amplifiers.

In total, the Alexa Fund has provided financial backing to more than 50 companies, including microphone maker Vespersales assistant Tact.ai, and smart home device makers Ecobee and Ring. Amazon acquired Ring in February, reportedly for more than $1 billion.

The Alexa Fund was established in 2015, and last year Amazon pledged to back more companies outside the United States.

Among other Alexa Fund-backed initiatives, more than a dozen new universities were chosen to participate in the Alexa Fund Fellowship to increase the use of conversational computing and voice AI research at colleges in various parts of the world.

Beyond backing for specific startups, to spur growth of the third-party ecosystem that now includes more than 50,000 Alexa skills, Amazon earlier this week announced the introduction of consumables so developers can charge users for things like special powers or extra lives when they are playing games and for ephemeral goods for non-gaming skills.

Acceptance of Amazon Pay within skills was also extended to the makers of skills outside the U.S. for the first time this week. In-skill purchasing was introduced in the U.S. in May.

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