1. A method, comprising: receiving, from a user, a string of characters; determining components of the string of characters, wherein the components of the string of characters comprise one or more graphemes that are related in the string of characters; determining universal phonetic representations for the components of the string of characters; determining pronunciations for the universal phonetic representations; constructing a pronunciation of the string of characters based at least partially on the pronunciations of the universal phonetic representations; sending, to the user, a sound file representing the pronunciation of the string of characters; receiving a user sound file created by the user using a microphone, the user sound file representing a custom pronunciation associated with a subset of the universal phonetic representations corresponding to a portion of the pronunciation of the string of characters; constructing a new pronunciation of the string of characters based at least partially on the pronunciations for the universal phonetic representations and the custom pronunciation associated with the subset of the universal phonetic representations; and sending, to the user, a new sound file representing the new pronunciation of the string of characters, wherein the new sound file comprises a combination of a portion of the sound file representing the pronunciation of the string of characters and the user sound file.