aGender contains speech sample recordings over public telephone lines with read and (semi-)spontaneous speech. Native German speakers called a voice portal from their private phone, and read text + answered some open questions. The purpose of the corpus is the automatic detection of gender and/or age (7 mixed classes ranging from 7 - 80 years). The corpus contains the voices of 945 German speakers (approx. minimum of 100 speakers per class), each delivering 18 speech items in up to six different sessions. The time/date of the individual recordings sessions were not controlled, neither the total number of sessions per speaker. The audio signal was recorded over standard cell phones (GSM standard) and landline connections in 8000 Hz, 8 bit alaw format. Data were then expanded to 8000Hz, 16bit PCM (all 16 bits are valid!). The selection of speakers is approximately evenly distributed over the seven target classes, with class 1 also being balanced for gender. The read material consists of an altered version of the SpeechDat text material, containing short fixed and free text typical for automated call centers. A typical utterance is about 2 seconds in length, but there are also some utterances are between 3 and 6 seconds. In total, the corpus consists of 47 hours of speech. Two sets were defined on that data: A training set (81.5%) and a test set (175 speakers, 25 per class, 18.5%), each with disjunctive speaker sets. For the test set no class information is given in this corpus. Number of speakers in training/development set: 770 Number of speakers in test set: 175 Number of sessions in train/devel: 3625 Number of utterances: 65241 Number of training/development utterances: 53076 Number of test utterances: 12165 For a general information, see also: Felix Burkhardt, Martin Eckert, Wiebke Johannsen, Joachim Stegmann (2010): A Database of Age and Gender Annotated Telephone Speech. In: Proceedings of the LREC 2010, Malta.