LTR or Listen Through Rate is an audio centric performance indicator for advertisers. It represents the ratio between the number of ads listened through to the end to the total number of impressions recorded for a campaign.
Due to the nature of listening activities it is common that LTR sits in the range of 90%+ and is a measure of how listeners are engaging with audio content in general.
A lower LTR could signal an audio ad that listeners do not engage with and prefer skipping it or stopping the stream altogether. For best performance and listener experience you should always aim at having a high LTR.