The quality of an audio file plays an important part in the price of the job. Naturally, clear sound is welcomed and many times will cost less. Nevertheless, sound with multiple unintelligible sections, background noises, and speakers who are cutting each other away or too far from the mic may lead to /hourly rates that are higher per minute. Some individuals do not mind paying more for transcription, but for those cash folks that are aware,
"Follow these rules and you may never need to pay additional for poor sound again. The transcription service will not be unhappy with the quality and you are going to not be unhappy with the cost. It is a win/win scenario.
This increases an automatic red flag the sound isn't great quality and it could wind up costing you more than anticipated since most transcription rates will quote a rate once they've listened to some sample of "poor sound.