Audio Attenuation + Sequencer for VR Film

Really struggling here, and I feel I’m so close but I just cant make this work… I’m creating a 4 minute VR film where a miniature person is going to speak to the viewer as part of the story-line. I therefore need to ad audio with attenuation to the sequencer. I get everything working apart from getting the audio attenuation to start a particular time.
Thank you!