A speech signal processing method of a user terminal, the speech signal processing method comprising: receiving a speech signal including a personalized information section (702, 709) and a general information section (701, 703) that is different from the personalized information section; transmitting the received speech signal to a server; and detecting the personalized information section including personal information in the speech signal and generating first speech section information that marks the personalized and general information sections; characterised by: performing data processing only on the personalized information section of the speech signal using a personalized model customized for a specific individual, thereby skipping data processing of the general information section of the speech signal by the personalized model, wherein the personalized model is at least one of a personalized speech recognition model, a personalized natural language understanding model, and a personalized lexical model; receiving, from the server, i) a result of data processing performed by the server on a general information section of the speech signal by a general model and ii) second speech section information that marks a personalized information section and the general information section of the speech signal generated by the server; and determining whether there is unprocessed speech data based on at least one of the first speech section information generated by the user terminal or the second speech section information received from the server, and, when it is determined that there is unprocessed speech data, performing data processing on the unprocessed speech data using the personalized model based on the second speech section information received from the server. receiving a speech signal including a personalized information section (702, 709) and a general information section (701, 703) that is different from the personalized information section; transmitting the received speech signal to a server; and detecting the personalized information section including personal information in the speech signal and generating first speech section information that marks the personalized and general information sections; characterised by: performing data processing only on the personalized information section of the speech signal using a personalized model customized for a specific individual, thereby skipping data processing of the general information section of the speech signal by the personalized model, wherein the personalized model is at least one of a personalized speech recognition model, a personalized natural language understanding model, and a personalized lexical model; receiving, from the server, i) a result of data processing performed by the server on a general information section of the speech signal by a general model and ii) second speech section information that marks a personalized information section and the general information section of the speech signal generated by the server; and determining whether there is unprocessed speech data based on at least one of the first speech section information generated by the user terminal or the second speech section information received from the server, and, when it is determined that there is unprocessed speech data, performing data processing on the unprocessed speech data using the personalized model based on the second speech section information received from the server. performing data processing only on the personalized information section of the speech signal using a personalized model customized for a specific individual, thereby skipping data processing of the general information section of the speech signal by the personalized model, wherein the personalized model is at least one of a personalized speech recognition model, a personalized natural language understanding model, and a personalized lexical model; receiving, from the server, i) a result of data processing performed by the server on a general information section of the speech signal by a general model and ii) second speech section information that marks a personalized information section and the general information section of the speech signal generated by the server; and determining whether there is unprocessed speech data based on at least one of the first speech section information generated by the user terminal or the second speech section information received from the server, and, when it is determined that there is unprocessed speech data, performing data processing on the unprocessed speech data using the personalized model based on the second speech section information received from the server.