@davekoh, I can't speak for all phones, but you should be able to buy an external mic for your phone. It may improve the transcriptions. The mic will make it more convenient to allow you to read the transcript while you position the mic as close to the speaker as possible. If the mic is more than about 8 inches from the speakers mouth, it may not help much. You may want to purchase the mic from a place that has a good return policy in the event the expectations are not met.
Tony in Michigan