2 rounds. First round was behavioral, second round was 2 hours with 4 mini interviews with 3 being technical and one being behavioral and architectural. Overall, it was not too bad and the interviewers were chill.
Technical question is the main part of this position. Acoustic design intern should be familiar with MEMS design, characteristics. If you are well-prepared technical person with formula and illustrations. That would be great.
The process was smooth. First round is screen and some technical questions, about 1 hour. Second round has 2.5h, all technical with 0.5h HR questions. Interviewee was nice, take your time and show how you solve the questions.