British-American branding firm Wolff Olins has created a shapeshifting logo for South African telecoms company Oi that changes colour and form in response to people's voices.

Volume increases the size of the logo, whereas changing pitches vary the colours and shape. Quiet, low voices create "calm" blue versions, whereas louder more high-pitched voices result in "a more wild and fluorescent symbol".

The new logo replaces the company's previous static "orange speech bobble", although features the same white cut-out lettering.

"We worked really hard to define the exact movement, shape and colours of the logo in response to sound," the firm's design director Campbell Butler told Dezeen."We wanted it to feel really organic and beautifully responsive to human voices."
The consultancy collaborated with digital design studio Onformative to develop custom software that allows anyone to use sound to transform the logo. It also allows users to save their own versions.

Moving, responsive versions of the symbol will be used in TV and other live action environments, whereas unique versions of the logo can be generated for print formats.

The firm has also created a modified version of the Simplon typeface, originally designed by foundry Swiss Typefaces, and a set of icons.

"People are at the heart of this brand," said Butler. "An important part of the brief was to develop icons and typography that could be easily 'rea...