sending a message "while a service node is being processed"

Hi, when waiting for a service call response, if it takes a long time, is there any way to send messages to the applicant such us “I am working on it” or “I am looking for the response”, to inform the applicant we are processing the request?
I would also like to know if there is any way to send audio sounds while waiting for the response, such us typing indicator, to indicate the user, that we are working on the request. Thank you.