The question comes up periodically: must I pray the Liturgy of the Hour out loud, or at least in a whisper, or at least moving my lips in order for it to be "valid" as liturgical prayer?
Nothing in the General Instruction on the Liturgy of the Hours spells this one out. And we get varying answers when we consult different priests. (and the variations I have gotten have nothing to do with said priests' personal orthodoxy, by the way. Priests of all persuasions have told me various things, although none have ever quoted me anything "official" as a source for their opinions.)
Some time ago a reader of this blog (a priest, in fact) showed me an official answer to this question. It appeared in a comment to a blog post, but I don't know that I ever put it in the body of a post. So here it is.
Sacred Congregation for Divine Worship Note Liturgiae Horarum Interpretationes (Not 9 (1973) 150)
Query: When a person recites the liturgy of the hours do the readings have to be pronounced or simply read?
Reply: It is enough to simply read them. The conciliar Constitution on the Liturgy says nothing about an obligation to oral recitation when a person says the office alone, although there was a difference of opinion on this among the conciliar Fathers. They decreed a reform of the breviary not for the purpose of shortening the time of prayer but of giving all who celebrate the liturgy of the hours a better time for prayer…Sometimes a surer guarantee for this objective of the liturgy of the hours in individual recitation may be to omit the oral recitation of each word, especially in the case of the readings.
Found on page 1098 of Documents on the Liturgy 1963-1979. Conciliar, Papal and Curial Texts. The Liturgical Press, 1982
I will add here that the priest who so nicely informed me of this also stated his understanding that if you are using the EF breviary (1961) said that if you are following the older discipline, that you do have to move your lips--that the old rules are still in force for the old breviary. If someone out there knows a lot about the EF breviary and its rubrics, and would like to elaborate on that, feel free to do so.
Plus, any other questions about the Liturgy of the Hours are welcome. Ryan Ellis, maybe?