Allah (swt) is aware of the inside of His servants, but at the same time, He has said that He likes it when they actually verbalize their needs and supplications and that such entails great rewards. Therefore, it is better not to replace reciting duas with listening to them just because it may be more convenient. Of course if there are certain problems that may prevent one from reciting or harden the process, and even in normal circumstances, listening to duas with focus and humility can have a positive impact and near one to Allah (swt), bringing him great blessings, nevertheless, it can't be said that for those who can do it, reciting is equal to listening of duas in reward.
The term “dua” refers to asking for needs and help and sometimes it is used for ‘calling’ in general. In Islamic terms, it means to ask Allah (swt) for needs.
Dua is one of the best forms of worship, because it shows one’s highest level of humility and expresses his servitude towards his lord. Dua has also been looked at as a form of worship in the Quran and hadiths; the Quran says: “Call me and I will answer you, Indeed those who avoid my worship out of arrogance will enter Hell in utter disgrace”.
Imam Sadiq (as) has said: “Call Allah (swt), for nothing can draw you closer to Allah (swt). Even in small matters, take refuge in Allah (swt), because even these small matters are solved by the same person in which great matters lie in the hands of.”
Therefore, if done with a pure intention, dua is a form of worship that can near one to Allah (swt) and bring him otherworldly rewards. Because of the following reasons, it is better for one to recite the dua himself in order to receive more rewards and not to limit himself to listening (in normal circumstances):
1- Words that derive from the root ‘دَعَوَ’ (dua being one of them) are usually used for cases in which there is verbalization, although they may also be used in the Quran for cases in which there is no verbalization.
2- If any hadiths mention rewards and other things for a certain dua, it is for the one reciting it, because Allah (swt) likes to hear the voice of His servant, as the prophet (pbuh) says: “Ask Allah (swt) out of His grace, for He likes the invocation of his servant.”
Imam Sadiq (as) says: “…for Allah (swt) knows of what His servant has on the inside, yet He likes for them to present their needs and call Him”
3- How can there be so many rewards for only listening to a dua without doing anything and how can it be considered a form of worship? Don’t you think that only listening while a dua is being recited is only a way of being more comfortable?!
4- Aside from receiving what one has asked Allah (swt) for, when he does dua, he has reached its main goal and the highest level of servitude, which is to call Allah (swt) and supplicate to him, and one who shows servitude to Him will receive His special attention, as He Himself says in the Quran: “If it wasn’t for your calls [to your lord], my lord would pay no attention to you”. In this verse, dua and calling Allah (swt) has been looked at as the means of man’s value through which he can draw Allah’s (swt) attention. Therefore, each servant needs to verbalize what he has on the inside and express it to his lord (of course, not that this has to always be done without any exception, but at the same time, he shouldn’t limit himself to only speaking with Allah (swt) with his heart).
5- One form of dua, is to cry and wail to Allah (swt), which signifies the highness and virtue of the person. It is because of this that Allah (swt) likes it when His servants do such. Of course, people differ, and some may even cry when listening to a dua, but can one say that all of the conditions, rulings and rewards that have been mentioned for doing dua, are all related only to the one who listens to duas?
The prophet of Islam (pbuh) says: “When Allah (swt) loves a servant of His, He gives him problems in order to hear his wailing voice [in supplication to Him].” What this hadith is telling us that matters in duas, is wailing and crying (It must be noted though that just because one doesn’t cry in his supplications, it doesn’t mean that they are no longer accepted; he should do duas anyway and not deprive himself of this great blessing).
To conclude from all of the above, each person should verbalize his/her needs for Allah (swt) and not limit him/herself to just listening. Of course, there are other points that must also be considered:
1- Hadiths recommend that duas be recited collectively, and that these duas might be answered quicker than duas recited individually; what needs to be pointed out though is that even in gatherings where duas are recited collectively, everyone needs to be reciting the dua and if a person doesn’t know how to recite the dua, it is okay and he will gain blessings as well, because speaking to Allah (swt) in any language and in any way, or listening to such all have rewards.
2- Humility before Allah (swt) itself is praiseworthy and brings thawab and rewards, even if not accompanied with the recitation or listening of a dua. If one ever accomplishes such through listening to a dua, he will be given great rewards, even if such rewards haven’t been promised for the dua itself (This shows the significance of humility before Allah (swt) and how it is the core of prayer and supplication that really please Him).
3- There are some exceptions for what we said above about verbalizing supplications; for instance, those who lack the faculty of speech or are in a situation that doesn’t allow them to recite (like while they are driving, etc.) and can only listen.
These people shouldn’t deprive themselves of listening to duas with the excuse of it not having any thawab; they can be sure that it has rewards for them.
Conclusion: If one wants to gain the specific rewards of certain duas, and has no excuse for not reciting the dua, he must recite it and speak to Allah (swt) in order for that to happen. Nevertheless, any spiritual link to Allah (swt), one of those being listening to a dua, has its own value.
1- The conditions for a dua being answered for sure, 197 (website: 983).
2- The conditions and ways for a dua to be answered, 2145 (website: 2269).
3- Quickly answered duas, 871 (website: 1087).
 Question 197 (website: 983).
 Muhammad ibn Ya’qub Kuleini, Kafi, vol. 2, pg. 467, hadith 6.
 Fatir:6 “إِنَّما یَدْعُوا حِزْبَهُ لِیَکُونُوا مِنْ أَصْحابِ السَّعیر”.
 Jalaluddin Suyuti, Al-Durrul-Manthur, pg. 149.
 Muhammad Baqir Majlisi, Biharul-Anwar, vol. 90, 296.
 Kafi, vol. 2, pg. 484.