Answer
Divide your time appropriately. Sometimes read, sometimes hear, and continue your devotional service.
Krishna resides within your heart and will inspire you to know what is most beneficial at a particular time. When you read, Krishna can bring the exact instruction you need, and that instruction will purify you.
Reading, chanting, and devotional service are all forms of Krishna consciousness. At our present stage, we cannot rigidly say that one practice is always superior to another.
Sometimes chanting more is exactly what we need.
At other times, because our consciousness is still materially conditioned, increasing our chanting without purification may simply result in more offensive chanting. In such situations, reading Srila Prabhupada's books may be the better medicine because it purifies our consciousness.
Therefore, we should faithfully follow the instruction given by the guru: chant sixteen attentive rounds every day and engage wholeheartedly in the preaching mission. This gradually destroys passion, material desires, and selfish enjoyment.
Eventually, a stage comes when these doubts disappear. You no longer wonder whether you should read more, chant more, or perform another service.
At that stage, Krishna personally guides the devotee from within the heart regarding which devotional service should be performed at each moment.
There is no need to impose a rigid formula, because the Lord in the heart directs the sincere devotee.
