If you're looking for a service that can process lots of audio files in a batch and that handles a variety of file formats, ai|coustics is a great option. This web app and API/SDK converts voice recordings into studio-quality audio with options for background noise reduction, echo cancellation and distortion filtering. It can handle more than 40 file formats, and you can process multiple files in a batch. That makes it good for podcasting, video editing and e-learning. Pricing plans are serious, with a free tier, so you should be able to find something that works for your needs and budget.
Another good option is Descript, a video and podcast editing service that uses AI. Descript offers multitrack audio editing, AI-selected clips, remote interviews, one-click captions and automatic transcription. It's more geared for editing, but it can handle a variety of file formats and can process files in a batch, so it's good for marketing, sales and learning and development teams. Pricing starts at $12 per person per month, and there's a free tier for limited use.
If you're interested in music mixing and mastering, Cryo Mix has AI tools to improve your audio. It includes AI Mixing to set the volume of vocals and otherwise fine tune settings, an AI Audio Separator to isolate individual stems, and a mastering tool to get industry-standard quality. It's more geared for music production, but its batch processing abilities and support for many file formats make it a good option for anyone who needs to process audio at high quality.