While there are plenty of free tools for development and art, for whatever reason I've always found it hardest to find good free audio tools. Here are some tools that I think are pretty useful for editing audio or creating music and sound effect.
Audacity is a cross-platform open source audio editor and recording tool created by Dominic Mazzoni and Roger Dannenberg in 1999. Several years later, it's still being developed, with new improvements coming every release.You can use Audacity to record live audio, record computer playback, perform noise removal, add audio effects, convert, edit or mix multiple types of audio formats, as well as export to multiple formats.Audacity also supports plugins and allows custom effects to be made using a programming language called Nyguist.
Some of the most basic uses of this softwarewould be to remove lag in podcasts where the speakers are in different locations. This would be done by every participant recording their own audio stream using Audacity, and afterward stitching every audio stream together in the editor while accounting for the lag that happened while recording.
Another simple use for this software would be creating sound effects, or splicing up an audio track in case you needed to remove parts of it to make it better loop in your game.
Bfxr is a browser-based synth program used for generating sound effects. Bfxr is based on Sfxr, a tool that was written during the 10th Ludum Dare, but has been extended over time with additional features. Bfxr has added new waveforms and filters, expanded the pitch and jump parameters, as well added a mixer and visualizer. It also allows for users to lock specific parameters during randomization and mutation for better control. Once you've created the sound effects you want,you can then download them as .wav files.
Top 5 Alternative Audio Tools
Audio is a web-based audio workstation which can be used to create music for your game. It also supports midi devices, and since it works within a browser you don't have to worry about installing any kind of software. The only downside you might find is that you have to publish your tracks to a public page. You still retain the copyright, but it does mean that the tracks will be seen by everyone.
LLMS is an open source cross-platform audio workstation that allows you to produce music. It supports midi devices, as well as a plugin system to extend the software.
This is tracker specially designed for creating NES/Famicom audio. This can be useful if you're interesting in creating a game that's trying to be a throwback to that era, or you're simply interested in seeing what you can produce with a more limited set of options.
milkytracker.org Milky is a popular cross-platform tracker used to create sound effects and music tracks for games. Milky exports to .mod, which is supported by popular game engines such as Unity.
OpenMPT is a tracker for Windows which allows you to create music and effects for your game. OpenMPT also supports a plugin system which allows it to extend the functionality of the software.
Finally, I've decided to throw in a few pieces of software we use on a day-to-day basis, or have found to be useful at various times.
Microsoft OneDrive onedrive.live.com/
One place for everything in your life .Keep all your files and photos in OneDrive. Access and share them from your phone, tablet and computer.
Google Docs docs.google.com
This comes in pretty handy if you're trying to put together documents for your project and want to collaborate with someone else.
Libre Office libreoffice.org
Libre Office is useful if you'd rather store all your documents locally, or know you're going to be without a connection and need to work on those spreadsheets!
BitBucket provides Git and Mercurial source control,a wiki, and issue tracker. Free accounts are provided for up to five users, but after that you'll need to start paying.
Github provides source control, a wiki, and issue track. Unfortunately, unlike BitBucket, all free accounts are publicly viewable unless you pay for a private account. However, a pretty neat feature in Github is Github pages. These allow users to create a static website for the projects they host there. A lot of users use this feature to host their own blogs. You could do the same thing for your game website and save yourself some money.
There are many project management tools out there, but unfortunately most of them are bloated, or filled with junk I don't think is particularly useful. Here are some free ones I've found myself going back to.
This software is used for team communication. It allows users to separate out conversations into different channels or topics to help keep track of conversations and issues. It also allows users to hook in different pieces of software, to provide different kinds of notifications to teams. To those who have used IRC it's essentially an IRC web front end with a bot.
Trello is used for creating, organizing and tracking tasks. This comes in really handy when collaborating with other people.
Teamwork without email.Asana puts conversations & tasks together,so you can get more done with less effort.
Feel free add any other resources which you are aware of .
Courtesy : Game Career Guide