A system comprising a server and a device, the server comprising: a memory storing one or more computer-readable instructions; a processor configured to execute the one or more computer-readable instructions stored in the memory; and a communication interface configured to receive, from the device, a first character string, the first character string being a text result output from speech recognition performed by the device of a speech signal input to the device, wherein the processor when executing the one or more computer-readable instructions is configured to: generate a plurality of estimated character strings to replace a portion of the first character string, based on the first character string, wherein each estimated character string of the plurality of estimated character strings is a character string in which at least one character within the first character string has been replaced by at least one replacement character, the replacement characters having pronunciations similar to the pronunciations of the characters they replace; select an estimated character string from among the plurality of estimated character strings based on a language model and dictionary information; and control the communication interface to transmit a second character string to the device, the second character string comprising the portion of the first character string replaced with the selected estimated character string. a memory storing one or more computer-readable instructions; a processor configured to execute the one or more computer-readable instructions stored in the memory; and a communication interface configured to receive, from the device, a first character string, the first character string being a text result output from speech recognition performed by the device of a speech signal input to the device, wherein the processor when executing the one or more computer-readable instructions is configured to: generate a plurality of estimated character strings to replace a portion of the first character string, based on the first character string, wherein each estimated character string of the plurality of estimated character strings is a character string in which at least one character within the first character string has been replaced by at least one replacement character, the replacement characters having pronunciations similar to the pronunciations of the characters they replace; select an estimated character string from among the plurality of estimated character strings based on a language model and dictionary information; and control the communication interface to transmit a second character string to the device, the second character string comprising the portion of the first character string replaced with the selected estimated character string. generate a plurality of estimated character strings to replace a portion of the first character string, based on the first character string, wherein each estimated character string of the plurality of estimated character strings is a character string in which at least one character within the first character string has been replaced by at least one replacement character, the replacement characters having pronunciations similar to the pronunciations of the characters they replace; select an estimated character string from among the plurality of estimated character strings based on a language model and dictionary information; and control the communication interface to transmit a second character string to the device, the second character string comprising the portion of the first character string replaced with the selected estimated character string.