Here are the sound files from the paper "Experiments on the Relationship between Perde and Seyir in Turkish Makam Music" by Can Akkoç, William A. Sethares, and M. Kemal Karaosmanoğlu, which is published in Music Perception. Detailed descriptions of the sound examples can be found in the paper. If the files do not play in your browser, you can download them by right-clicking and choosing save-as. You can find a version of the paper here

First are the 17 taksims performed by Niyaz Sayin from which the sound examples were constructed. These are in the following makams:

Buselik
Evic
Hicaz
Hicazkar
Huseyni
Isfahan
Mahur
Muhayyer
Neva
Nihavend
Rast
Saba
Segah
Sultaniyegah
Suzinak
Ussak
Yegah

The sound examples for the experiments are divided into groups. For Experiment #1, the sound examples are:

hicaz-synth.mp3
isfahan-synth.mp3
muhayyer-synth.mp3
neva-synth.mp3
rast-synth.mp3
ussak-synth.mp3

which correspond to the midi files

hicaz-synth.mid
isafan-synth.mid
muhayyer-synth.mid
neva-synth.mid
rast-synth.mid
ussak-synth.mid

The sound examples for Experment #2 are:

hicazkar135724689.mp3
hicazkar183754629.mp3
hicazRev.mp3
mahurLinear.mp3
mahurRev.mp3
ussakRev.mp3

The sound examples for Experment #3 are:

hicazRand1.mp3
hicazRand3.mp3
rast-13572468.mp3
rast-17654328.mp3
ussakRand1.mp3
ussakRand3.mp3

The sound examples for Experment #4 are:

perHusSeyMah.mp3
perMahSeyHus.mp3
perMuhSeyUss.mp3
perNivSeySuz.mp3
perNivSeyYeg.mp3
perUssSeyMuh.mp3
perYegSeyNiv.mp3