Besides Audacity, what software are there for audio enhancement? Basically, I'm interested in speech audio. Cleaning of background noise can be done really well with Audacity, but what else can be done to improve speech understanding, or to establish the identity of the speakers? Or maybe for getting an insight into age or gender of speaker (more in the sense of forensics)?
I can be for Linux, iOS or Windows, commercial or open source.
You didn't provide your OS and price requirements. If you want paid solution and OS is Windows here are two alternatives for Audacity.
Option 1: Adobe Audition
Edit, mix, record, and restore audio.
Audition CC is a comprehensive toolset that includes multitrack, waveform, and spectral display for creating, mixing, editing, and restoring audio content. This powerful audio workstation is designed to accelerate video production workflows and audio finishing — and deliver a polished mix with pristine sound.
Source: adobe.com
Option 2: Sound Forge
Free, high-quality solution for music and audio editing.
Start recording with a click using the redesigned recording dialog. Select between threshold, MTC or timestamp recording via the recording options. Record on up to 32 tracks simultaneously and in ultra-high-resolution audio in 64-bit/192 kHz.
Sound design
Includes an impressive range of editing functions for advanced editing: convert regions to events, lock event markers, region markers, and envelope points to events, and automatically ripple successive events forward in time while editing.
Audio editing
Plug-ins from specialists such as iZotope® and zplane. SpectraLayers Pro now seamlessly integrated for comprehensive spectral editing. Everything you need in one fully customizable user interface.
Post production
Master your audio and video projects with effects from iZotope®. Create DAO CD masterings to Red Book specification. Or export multichannel files in surround AC-3 format using the included Dolby Digital AC-3 plug-in.
Source: magix.com
More information about Sound Forge
Edit: If you need more professional software you could try Cubase.
