<ul data-eligibleForWebStory="true">Spotify introduced audiobook access and raised pricing for Premium plans last year.Senators believe consumers weren't adequately informed about the changes and accuse Spotify of reducing payouts to musicians.Senators are petitioning the FTC to intervene.The Premium plan price was increased from $11 to $12 per month.The increase was accompanied by access to 15 hours of audiobook streams each month.