The invention relates to a device (1) at least for an acoustic temperature measurement in a gaseous medium (M) passing a medium channel (110) by means of runtime measurement of an acoustic pulse (AP) running through the gaseous medium (M) from at least a first transmitter arrangement (TA1) to at least a first receiver arrangement (RA1), the first transmitter arrangement (TA1) comprising a sound pulse generator (2) for the generating the acoustic pulse (AP), which is connected by a first acoustic channel (3) to a transmitter (4) which transmits the acoustic pulse (AP) into the medium (M), the first acoustic channel (3) being of acoustically dispersive design, and, the first receiver arrangement (RA1) comprising a receiver (5) for receiving the acoustic pulse (AP) after it has passed through the medium (M) and for transmitting it via a second acoustic channel (6) to a first microphone (7), preferably a piezoelectric microphone (7), for detecting the acoustic pulse (AP), the first acoustic channel (3) being curved towards the sound pulse generator (2) in such a way that the radiant heat of the medium (M) on the sound pulse generator (2) is at least greatly reduced, wherein at least the transmitter (4) comprises in the first acoustic channel (3) on its side (41) facing the medium (M) to be measured interfering element (42) which reflects a part (RI) of the acoustic pulse (AP) back into the first acoustic channel (3) of the first transmitter arrangement (TA1), in which a second microphone (8), preferably arranged on the side (43) of the transmitter (4) feeing the sound pulse generator (2), is arranged for detecting the back-reflected part (RI) of the acoustic pulse (AP), the device (1) further comprising a pulse discriminator (9) designed to determine the arrival times (AT) of the recorded acoustic pulses (AP) in a suitable way and to transmit them to an evaluation unit (10) designed to determine the temperature of the medium (M) from the runtime of the acoustic pulse (AP) from the transmitter (4) to the receiver (5), taking into account the arrival times (AT) determined by the pulse discriminator and the acoustic pulses (RI, AI) detected by first and second microphones (7,8).