The development of Clara and Bruno (a Spanish male) started around 2009. To find their voices a casting was set up which included ESMUC's students, professional and amateur singers. From that casting two candidates were chosen, a male and a female. The creation of the voicebanks wasn't continued immediately, as first it was required to adapt VOCALOID's engine to the Spanish and found the company for their creation.
Her demos were revealed October 21, 2011. She and Bruno were released on the 23rd of December. Their production was aided by Giuseppe.
Upon their first release, they were only able to be bought via download and buyers had to use a non-free e-mail account to purchase them. This was to prevent credit card fraud. The problem was not Voctro Labs, but rather the retail seller Share-it's rules for sale. They come without the full editor, but could be bought together or separately. Their joint package made them the cheapest of the VOCALOID3 voicebanks upon their release, despite the user having to purchase the full VOCALOID3 editor separately.
Finally on January 26, a month after their release, they were made available to buy using PayPal, and customers could use a free e-mail account.
On February 21, Voctro Labs put physical copies of the both Clara and Bruno up for sale, along with a new illustration.
Clara is Bruno's counterpart and is a mature female vocal.
Reported to be overall quite understandable by Spanish fans/users.
Her voice is quite flexible, standing well the GEN changes or filters that modifies her pitch/timbre.
Her vocal is better suited for higher octaves than lower. It has been noted by various Clara users that in her lower range she lacks depth.
Being nasally and soft, her voice has little strength behind it.
In comparison to Bruno, Clara is considered harder to use.
When using the phonemes [x] and [U] together, Clara will make a static sound instead of pronouncing the sound. This is due to a glitch that the [U] phoneme is not meant to be used on its own in the Spanish language.
There has also been minor pronunciation issues reported that relate to her R, this one may be distorted by the nearby phonemes when is at the end of a syllable.
Has Iberian Spanish accent which is noticed in the addition of the phoneme [T] and the apical pronunciation [s] phoneme, which gives it certain "whistling" or SH-like quality.